1 00:00:15,410 --> 00:00:26,130 Speaker 1: Pushkin. Henry Petrotski was, and I mean this as a 2 00:00:26,170 --> 00:00:31,410 Speaker 1: most sincere compliment, a nerd. This is a man who 3 00:00:31,450 --> 00:00:35,050 Speaker 1: wrote a four hundred page history of the toothpick and 4 00:00:35,130 --> 00:00:37,450 Speaker 1: even managed to get that book reviewed in the New 5 00:00:37,530 --> 00:00:40,330 Speaker 1: York Times, even if the reviewer did tell him to 6 00:00:40,370 --> 00:00:43,090 Speaker 1: knock it off. I never read the Toothpick book, I 7 00:00:43,130 --> 00:00:45,610 Speaker 1: have to admit, but I did read other books by 8 00:00:45,690 --> 00:00:49,290 Speaker 1: Dr Petrowski, and I love them. His history of the 9 00:00:49,370 --> 00:00:54,010 Speaker 1: pencil is amazing. Now, we economists have a strange relationship 10 00:00:54,010 --> 00:00:57,930 Speaker 1: with pencils because a classic essay in economics titled Eye 11 00:00:58,010 --> 00:01:01,290 Speaker 1: Pencil is kind of an autobiography of a pencil, which 12 00:01:01,330 --> 00:01:05,690 Speaker 1: explains the decentralized genius of the free market economy. But 13 00:01:05,810 --> 00:01:10,090 Speaker 1: Petrotski went way deeper into pencils, where they came from, 14 00:01:10,210 --> 00:01:13,010 Speaker 1: how we overlook them, even how they get the lead 15 00:01:13,290 --> 00:01:16,930 Speaker 1: into the middle of the pencil. He meditated on their 16 00:01:17,010 --> 00:01:22,490 Speaker 1: erasability so indispensable to designers and engineers. Ink is the 17 00:01:22,570 --> 00:01:26,490 Speaker 1: cosmetic that ideas will wear when they go out in public. 18 00:01:26,810 --> 00:01:32,570 Speaker 1: He wrote, Graphite is their dirty truth. Exhibit A in 19 00:01:32,690 --> 00:01:36,610 Speaker 1: Overlooking the Pencil is Henry David Threau, the great nineteenth 20 00:01:36,650 --> 00:01:41,050 Speaker 1: century American essayist. He once made a comprehensive list of 21 00:01:41,090 --> 00:01:45,170 Speaker 1: supplies for an excursion, specifying obvious items such as a 22 00:01:45,290 --> 00:01:49,930 Speaker 1: tent and matches, adding string, old newspapers, a tape measure, 23 00:01:50,090 --> 00:01:53,810 Speaker 1: and a magnifying glass, also including paper and stamps to 24 00:01:53,890 --> 00:01:57,410 Speaker 1: make notes and write letters. But as Petrotski points out, 25 00:01:57,650 --> 00:02:01,370 Speaker 1: isn't it strange that he omitted to mention the very 26 00:02:01,530 --> 00:02:05,090 Speaker 1: pencil with which he was making the list. Well maybe not, 27 00:02:05,210 --> 00:02:08,650 Speaker 1: you think, until you realize that Threau and his father 28 00:02:09,250 --> 00:02:14,130 Speaker 1: made their money by manufacturing high quality pencils. For row 29 00:02:14,530 --> 00:02:18,210 Speaker 1: was big pencil. As for that perennial question about the 30 00:02:18,210 --> 00:02:20,250 Speaker 1: pencil lead, and by the way, it's not lead, and 31 00:02:20,290 --> 00:02:23,210 Speaker 1: it's never been lead. Pencil leads are made from graphite. 32 00:02:23,450 --> 00:02:26,050 Speaker 1: When they first discovered graphite in the English Lake district 33 00:02:26,290 --> 00:02:28,890 Speaker 1: underneath the roots of an old tree that was uprooted 34 00:02:28,930 --> 00:02:31,330 Speaker 1: in a storm, well they didn't know what it was 35 00:02:31,690 --> 00:02:35,890 Speaker 1: and they called it black lead. But I digress. How 36 00:02:35,890 --> 00:02:38,730 Speaker 1: do they get the graphite inside the wood? The trick 37 00:02:39,050 --> 00:02:42,010 Speaker 1: is to take a slim slab of kiln dried wood 38 00:02:42,410 --> 00:02:46,170 Speaker 1: and saw a row of grooves into the top surface. 39 00:02:46,730 --> 00:02:49,890 Speaker 1: Originally the grooves were square easier to cut by hand, 40 00:02:50,610 --> 00:02:54,410 Speaker 1: now their precision machined with a semi circular cross section. 41 00:02:55,290 --> 00:02:58,090 Speaker 1: Once the cylindrical rods are laid into the grooves, you 42 00:02:58,170 --> 00:03:01,850 Speaker 1: glue another grooved slab on top, this time with the 43 00:03:01,890 --> 00:03:04,370 Speaker 1: grooves in the bottom. Then all you have to do 44 00:03:04,490 --> 00:03:08,930 Speaker 1: is cut the whole graphite sandwich into sticks parallel to 45 00:03:08,970 --> 00:03:14,450 Speaker 1: the graphite rods. Those sticks are unformed, pencils, plane, varnish, 46 00:03:15,010 --> 00:03:17,970 Speaker 1: and the chops done. And that is what you learn 47 00:03:18,370 --> 00:03:23,490 Speaker 1: if you read Henry Petrowsky. But Petrotski was not only 48 00:03:23,570 --> 00:03:26,410 Speaker 1: a toothpick and pencil guy, not at all. He was 49 00:03:26,410 --> 00:03:30,730 Speaker 1: an engineer, and a particular kind of engineer. He was 50 00:03:30,810 --> 00:03:35,250 Speaker 1: fascinated by failure. You can understand why I'm such a 51 00:03:35,290 --> 00:03:38,330 Speaker 1: fan of the man, He once told The New York Times. 52 00:03:38,570 --> 00:03:44,610 Speaker 1: Successful engineering is all about understanding how things break or fail. 53 00:03:45,730 --> 00:03:49,650 Speaker 1: One of his books, Success Through Failure, explored the way 54 00:03:49,690 --> 00:03:53,370 Speaker 1: that engineers often advanced the field by building more and 55 00:03:53,490 --> 00:03:58,090 Speaker 1: more ambitious buildings, till eventually they exceeded what was possible 56 00:03:58,290 --> 00:04:02,010 Speaker 1: and something broke a bridge, a wall, a concrete multi 57 00:04:02,010 --> 00:04:06,930 Speaker 1: story car park. The engineers learned, adapted, and moved on. 58 00:04:07,930 --> 00:04:10,050 Speaker 1: That was one of the inspirations for my own book, 59 00:04:10,250 --> 00:04:14,770 Speaker 1: adapt and Petrovsky was really really thoughtful on the subject 60 00:04:14,890 --> 00:04:20,570 Speaker 1: of engineering failure. In nineteen eighty one, two skywalks at 61 00:04:20,570 --> 00:04:25,690 Speaker 1: the Kansas City Hiatt Regency hotel collapsed, killing one hundred 62 00:04:25,730 --> 00:04:30,650 Speaker 1: and fourteen people. Dr Petrowski's neighbor asked him, how on 63 00:04:30,690 --> 00:04:34,970 Speaker 1: earth could that happen? Did engineers really not understand how 64 00:04:34,970 --> 00:04:38,570 Speaker 1: to build a simple structure like a walkway hanging from 65 00:04:38,570 --> 00:04:42,850 Speaker 1: a ceiling? And so Petrotski thought about that and went 66 00:04:42,890 --> 00:04:45,850 Speaker 1: on to write some of the most interesting analysis of 67 00:04:45,890 --> 00:04:49,650 Speaker 1: the disaster. His writing really helped me think through the 68 00:04:49,690 --> 00:04:53,490 Speaker 1: catastrophe at the Hiatt Regency, and it helped me think 69 00:04:53,530 --> 00:04:58,850 Speaker 1: through a lot more. Henry Petrowski died in June twenty 70 00:04:58,890 --> 00:05:02,450 Speaker 1: twenty three at the age of eighty one. He leaves 71 00:05:02,490 --> 00:05:06,890 Speaker 1: behind a shelf full of insightful books. Whether you're inter 72 00:05:07,010 --> 00:05:12,050 Speaker 1: engineering failure, or into pencil, or even Heaven forbid, into toothpicks, 73 00:05:12,450 --> 00:05:17,170 Speaker 1: Petrosky is your man. We'll be back in two weeks 74 00:05:17,210 --> 00:05:20,850 Speaker 1: with another brand new episode of Cautionary Tales, but this 75 00:05:20,930 --> 00:05:24,970 Speaker 1: week we're going to rerun a classic death on the 76 00:05:25,090 --> 00:05:28,890 Speaker 1: dance floor. It's a harrowing story about the collapse of 77 00:05:28,930 --> 00:05:32,090 Speaker 1: the Kansas City Skywalks. But like the best of our 78 00:05:32,130 --> 00:05:36,210 Speaker 1: cautionary tales, it's also a story that will, I hope, 79 00:05:36,970 --> 00:05:42,050 Speaker 1: make you think. Henry Petrowski made me think long and 80 00:05:42,210 --> 00:05:46,490 Speaker 1: hard about the skywalks. I hope something of that spirit 81 00:05:46,850 --> 00:06:13,690 Speaker 1: has rubbed off on the podcast. Friday Night at the 82 00:06:13,770 --> 00:06:17,730 Speaker 1: Hyatt Regency one of Kansas City's most popular dates since 83 00:06:17,770 --> 00:06:21,450 Speaker 1: the hotel opened just a year earlier. There are cues 84 00:06:21,490 --> 00:06:24,890 Speaker 1: at the lobby bar. The place is buzzing. It's the 85 00:06:24,930 --> 00:06:28,370 Speaker 1: summer of nineteen eighty one, but the orchestra is belting 86 00:06:28,370 --> 00:06:31,290 Speaker 1: out the big band sounds of the forties and fifties. 87 00:06:32,530 --> 00:06:35,770 Speaker 1: Dance contestants with numbers pinned to their backs are doing 88 00:06:35,810 --> 00:06:39,730 Speaker 1: the Mambo and the East Coast Swing. But while the 89 00:06:39,810 --> 00:06:45,050 Speaker 1: music is nostalgic, the hotel lobby is distinctly space age. 90 00:06:45,610 --> 00:06:48,690 Speaker 1: It's big and airy, with a glass wall letting in 91 00:06:48,730 --> 00:06:53,890 Speaker 1: the light and three walkways skywalks crossing the space on 92 00:06:53,970 --> 00:06:58,290 Speaker 1: the second, third, and fourth floors. They're suspended from the 93 00:06:58,370 --> 00:07:02,530 Speaker 1: ceiling so that the lobby itself is unobstructed by columns, 94 00:07:02,890 --> 00:07:07,930 Speaker 1: all the more room for dancing Cindy Paulson briefly looks 95 00:07:07,970 --> 00:07:10,330 Speaker 1: down from the terrace rest to see if she can 96 00:07:10,370 --> 00:07:13,970 Speaker 1: see her father out on the dance floor the restaurant. 97 00:07:14,130 --> 00:07:17,930 Speaker 1: On a large mezzanine overlooking the lobby provides the perfect view, 98 00:07:18,850 --> 00:07:21,530 Speaker 1: but the lobby floor is packed and she can't pick 99 00:07:21,570 --> 00:07:24,570 Speaker 1: him out of the crowd. After a moment, she goes 100 00:07:24,610 --> 00:07:28,890 Speaker 1: back to work. Cindy's a college student, her family live 101 00:07:28,970 --> 00:07:32,010 Speaker 1: in town. Being a hostess at the Hyatt is her 102 00:07:32,050 --> 00:07:38,130 Speaker 1: summer job. It's five past seven in the evening. Cindy 103 00:07:38,210 --> 00:07:42,370 Speaker 1: will always remember that because she glances across the lobby, 104 00:07:42,770 --> 00:07:46,050 Speaker 1: out through the floor to ceiling glass wall, and sees 105 00:07:46,090 --> 00:07:48,810 Speaker 1: the time on the clock on the bank just across 106 00:07:48,810 --> 00:07:55,170 Speaker 1: the street. Then, as a sharp crack, clearly audible even 107 00:07:55,210 --> 00:07:59,210 Speaker 1: above the music and the loud buzz of conversation, Cindy's 108 00:07:59,250 --> 00:08:03,090 Speaker 1: eyes refocus from the distant clock to the sky walks 109 00:08:03,130 --> 00:08:07,930 Speaker 1: in front of her, but she can't believe what she's seeing. 110 00:08:12,410 --> 00:08:40,370 Speaker 1: I'm Tim Harford and you're listening to cautionary tales. Dr 111 00:08:40,490 --> 00:08:44,930 Speaker 1: Joseph Wackerley got the call almost immediately from emergency dispatchers. 112 00:08:45,810 --> 00:08:48,730 Speaker 1: We need you at a hiat he grabbed a stethoscope 113 00:08:48,770 --> 00:08:52,770 Speaker 1: and scrubs and ran to his car. Wackerley, just thirty 114 00:08:52,810 --> 00:08:55,650 Speaker 1: five years old, had already served as the director of 115 00:08:55,810 --> 00:08:59,890 Speaker 1: Kansas City's emergency medical system. He rushed to the scene. 116 00:09:01,730 --> 00:09:04,410 Speaker 1: When Wackley arrived at the hyat, it was lit by 117 00:09:04,450 --> 00:09:07,810 Speaker 1: the flashing lights of ambulances. Amid the crowd. There were 118 00:09:07,850 --> 00:09:12,370 Speaker 1: dozens of injured people. Some were bleeding, others had broken bones. 119 00:09:12,730 --> 00:09:17,450 Speaker 1: Some were lying on stretchers. Wackley sprang into action, checking 120 00:09:17,530 --> 00:09:23,570 Speaker 1: who needed assistance most urgently. Then a paramedic grabbed him. 121 00:09:23,810 --> 00:09:27,090 Speaker 1: You're in the wrong place, he said. The real casualties 122 00:09:27,370 --> 00:09:32,730 Speaker 1: are inside the hotel. You need to get inside. The 123 00:09:32,770 --> 00:09:36,450 Speaker 1: lobby was no longer airy and bathed in evening sunlight. 124 00:09:37,250 --> 00:09:42,490 Speaker 1: It was coated in concrete dust. The skywalks no longer 125 00:09:42,610 --> 00:09:47,570 Speaker 1: levitated across the atrium. Two of them had fallen, crunching 126 00:09:47,650 --> 00:09:51,850 Speaker 1: onto the busy dance floor. Voices were calling out for help. 127 00:09:52,530 --> 00:09:57,570 Speaker 1: Electric cables were swinging loose arcs of electricity, sending flashes 128 00:09:57,610 --> 00:10:02,170 Speaker 1: of light across the dim space. Somewhere high above, a 129 00:10:02,210 --> 00:10:06,450 Speaker 1: pipe had fractured and water was gushing onto the lobby floor. 130 00:10:07,690 --> 00:10:11,250 Speaker 1: It was six inches deep. Or ready and threatened to 131 00:10:11,290 --> 00:10:16,050 Speaker 1: submerge those who were trapped if anyone had survived the impact. 132 00:10:16,170 --> 00:10:20,770 Speaker 1: That is, Wackerley could see arms and legs sticking out 133 00:10:20,810 --> 00:10:25,210 Speaker 1: of the rubble. Dr Wackerley took charge of the medical operation. 134 00:10:25,850 --> 00:10:29,890 Speaker 1: It was bolstered by a huge voluntary effort, with taxis, buses, 135 00:10:29,930 --> 00:10:33,370 Speaker 1: and private cars helping the ambulances to get injured people 136 00:10:33,370 --> 00:10:37,050 Speaker 1: to hospitals. Locals were doing whatever they could to tend 137 00:10:37,050 --> 00:10:40,890 Speaker 1: to the walking, wounded, free the trapped, and comfort families. 138 00:10:42,810 --> 00:10:47,410 Speaker 1: Among them was Cindy Paulson, the restaurant hostess. She'd helped 139 00:10:47,450 --> 00:10:50,530 Speaker 1: evacuate the diners at the restaurant, but then she'd return 140 00:10:50,610 --> 00:10:54,330 Speaker 1: to the lobby. Somewhere in the middle of that mess 141 00:10:55,170 --> 00:10:59,290 Speaker 1: was her father. She moved through the lobby, doing what 142 00:10:59,330 --> 00:11:03,290 Speaker 1: she could. She comforted one couple pinned under the wreckage. 143 00:11:03,850 --> 00:11:07,490 Speaker 1: After firefighters were able to free them, Cindy kept looking 144 00:11:07,690 --> 00:11:14,810 Speaker 1: for her father. Two hundred and fifty miles away in 145 00:11:14,850 --> 00:11:19,490 Speaker 1: Saint Louis, Jack Gillum and his wife arrived home to 146 00:11:19,570 --> 00:11:24,210 Speaker 1: find the telephone ringing. The call was from one of 147 00:11:24,250 --> 00:11:28,730 Speaker 1: the architects at the Hyatt Regency Hotel. There's been a 148 00:11:28,770 --> 00:11:34,730 Speaker 1: collapse at the Hyatt. Jack Gillum was stunned. He was 149 00:11:34,770 --> 00:11:39,450 Speaker 1: the structural engineer of record for the Hiatt Regency Hotel's construction. 150 00:11:40,170 --> 00:11:42,690 Speaker 1: That meant he was the one who had signed off 151 00:11:42,730 --> 00:11:46,370 Speaker 1: on all the designs, certifying that they were safe. And 152 00:11:46,410 --> 00:11:50,130 Speaker 1: now Gillam was being told that those elegant walkways across 153 00:11:50,170 --> 00:11:54,610 Speaker 1: the hotel lobby had fallen out of the sky and 154 00:11:54,730 --> 00:11:59,170 Speaker 1: smashed into the crowd of people below. Jack, the rescue 155 00:11:59,170 --> 00:12:01,330 Speaker 1: teams are trying to get equipment that can move the 156 00:12:01,370 --> 00:12:04,690 Speaker 1: fallen sections of walkway. They need to know how heavy 157 00:12:04,730 --> 00:12:09,970 Speaker 1: the sections are reeling. Gillam could hardly think. He stammered 158 00:12:09,970 --> 00:12:14,450 Speaker 1: out an approximate answer. Each of those airy looking skywalks 159 00:12:14,890 --> 00:12:20,250 Speaker 1: weighed over thirty tons. A single walkway section weighed about 160 00:12:20,290 --> 00:12:25,810 Speaker 1: eight tons. They were going to need cranes. Gillham managed 161 00:12:25,850 --> 00:12:29,170 Speaker 1: to charter a plane and fly over, arriving a few 162 00:12:29,330 --> 00:12:33,250 Speaker 1: hours into the rescue effort. Whatever he expected to see, 163 00:12:33,930 --> 00:12:37,570 Speaker 1: the disaster was worse, But his job now was to 164 00:12:37,570 --> 00:12:41,290 Speaker 1: try to figure out how the structure had failed. This 165 00:12:41,450 --> 00:12:44,930 Speaker 1: was a brand new building. It looked bold, but the 166 00:12:44,970 --> 00:12:51,650 Speaker 1: engineering was simple enough. Somehow the structure had failed catastrophically. 167 00:12:53,010 --> 00:13:01,730 Speaker 1: Somehow they'd missed something. But what Three skywalks had spanned 168 00:13:01,770 --> 00:13:05,690 Speaker 1: the atrium of the highest regency, flat decks of steel 169 00:13:05,810 --> 00:13:10,450 Speaker 1: and concrete with glass balustrades hanging on steel rods from 170 00:13:10,490 --> 00:13:15,090 Speaker 1: the roof. The third floor skywalk hung by itself and 171 00:13:15,290 --> 00:13:19,530 Speaker 1: was undamaged, but the second floor skywalk had hung directly 172 00:13:19,570 --> 00:13:23,130 Speaker 1: beneath the one on the fourth floor. When Cindy Paulson 173 00:13:23,370 --> 00:13:26,290 Speaker 1: had gazed absently over the lobby at a clock across 174 00:13:26,330 --> 00:13:29,890 Speaker 1: the street, her attention had been caught by the sound 175 00:13:29,970 --> 00:13:35,010 Speaker 1: of both skywalks lurching downwards a few inches. There were 176 00:13:35,050 --> 00:13:37,890 Speaker 1: a few people on the upper skywalk and more on 177 00:13:37,930 --> 00:13:41,250 Speaker 1: the lower one, fifty sixty maybe, but there wasn't time 178 00:13:41,250 --> 00:13:47,130 Speaker 1: for them to react. A moment later, both skywalks simultaneously 179 00:13:47,170 --> 00:13:50,810 Speaker 1: tore free of one of the supporting ceiling rods. The 180 00:13:50,890 --> 00:13:55,010 Speaker 1: extra load was suddenly transferred to nearby rods, ripping the 181 00:13:55,010 --> 00:13:59,690 Speaker 1: skywalks free of those connections too. From the nest and 182 00:13:59,810 --> 00:14:05,490 Speaker 1: the next the skywalks simply unzipped themselves from the ceiling rods, 183 00:14:06,170 --> 00:14:13,050 Speaker 1: and the skywalks no longer more than sixty tons of 184 00:14:13,090 --> 00:14:18,290 Speaker 1: steel and concrete fell onto the dancers below, spraying bystanders 185 00:14:18,290 --> 00:14:24,050 Speaker 1: with deadly glass shrapnel. The entire chain reaction took seconds. 186 00:14:25,410 --> 00:14:28,690 Speaker 1: Dr Joseph Wackerley and the other rescuers were now trying 187 00:14:28,730 --> 00:14:32,810 Speaker 1: to deal with the aftermath. One man was half buried, 188 00:14:33,250 --> 00:14:37,370 Speaker 1: his legs crushed by a piece of skywalk. Wackerley told 189 00:14:37,450 --> 00:14:41,290 Speaker 1: him he wouldn't survive unless they could amputate. The man 190 00:14:41,330 --> 00:14:46,650 Speaker 1: said no. Others didn't get the choice. Medics were forced 191 00:14:46,650 --> 00:14:49,250 Speaker 1: to tell people, we can't get you out in time. 192 00:14:50,050 --> 00:14:52,610 Speaker 1: You'll die before they get the cranes in here. All 193 00:14:52,610 --> 00:14:54,730 Speaker 1: we can do is give you something to ease the pain. 194 00:14:55,970 --> 00:15:01,170 Speaker 1: Then they moved on to the next patient. Family members 195 00:15:01,210 --> 00:15:04,450 Speaker 1: were on the scene almost immediately, begging the medics and 196 00:15:04,490 --> 00:15:08,610 Speaker 1: the fire crews to help. Wackerley was trying to decide 197 00:15:08,690 --> 00:15:13,610 Speaker 1: who most urgently needed care, with the spouses and parents 198 00:15:13,690 --> 00:15:18,690 Speaker 1: and children of the victims right there crying, pleading, screaming. 199 00:15:19,010 --> 00:15:22,290 Speaker 1: As he did it, he went back to the man 200 00:15:22,330 --> 00:15:26,170 Speaker 1: who had turned down the amputation. I've changed my mind, Doc, 201 00:15:26,370 --> 00:15:28,850 Speaker 1: he said, you can take my legs off. I just 202 00:15:28,890 --> 00:15:33,010 Speaker 1: want to live. Wackley beckoned over a surgeon with a 203 00:15:33,090 --> 00:15:38,370 Speaker 1: chainsaw to perform the amputation. They got him out, but 204 00:15:38,850 --> 00:15:44,290 Speaker 1: in vain. He didn't survive the night. Cindy Paulson was 205 00:15:44,410 --> 00:15:47,890 Speaker 1: outside looking for her father, hoping he'd been able to 206 00:15:47,930 --> 00:15:53,410 Speaker 1: walk away, and deep deep under the rubble was a 207 00:15:53,450 --> 00:15:57,930 Speaker 1: man called Mark Williams. Williams was an old school friend 208 00:15:57,970 --> 00:16:02,490 Speaker 1: of Joseph Wackerley. While Wackerley hurried around directing the medical response, 209 00:16:02,890 --> 00:16:06,650 Speaker 1: Williams was doing his best to contribute. He was trapped 210 00:16:06,770 --> 00:16:09,930 Speaker 1: in an eighteen inch pocket of air underneath a section 211 00:16:10,130 --> 00:16:13,970 Speaker 1: of fallen skywalk. His legs had been slightly askew when 212 00:16:14,010 --> 00:16:18,210 Speaker 1: the skywalks fell and were wrenched into the splits and beyond. 213 00:16:19,010 --> 00:16:22,930 Speaker 1: Both his legs were dislocated. His left foot was up 214 00:16:22,970 --> 00:16:27,570 Speaker 1: beside his right ear, but other trapped people could hear 215 00:16:27,650 --> 00:16:31,570 Speaker 1: his voice, calmly talking to them, trying to reassure everyone 216 00:16:31,850 --> 00:16:34,690 Speaker 1: that help was on the way, that they'd get through this. 217 00:16:35,970 --> 00:16:39,370 Speaker 1: But with his face pressed against the floor and water 218 00:16:39,530 --> 00:16:43,290 Speaker 1: seeping through the rubble all around him, Williams realized that 219 00:16:43,530 --> 00:16:48,290 Speaker 1: after surviving over sixty tons falling on him, he was 220 00:16:48,370 --> 00:17:08,730 Speaker 1: now all too likely to drown. While the medics and 221 00:17:08,770 --> 00:17:12,650 Speaker 1: the fire fighters worked through the night, the structural engineer 222 00:17:12,770 --> 00:17:16,370 Speaker 1: Jack Gillum wasn't getting any sleep either. He was the 223 00:17:16,370 --> 00:17:19,530 Speaker 1: man who'd officially declared the skywalks were safe to build. 224 00:17:20,490 --> 00:17:24,810 Speaker 1: What had gone wrong was a very simple and surprising mistake. 225 00:17:25,370 --> 00:17:29,890 Speaker 1: Gillam spent some time doing some calculations to confirm his suspicions. 226 00:17:30,490 --> 00:17:33,650 Speaker 1: Then he went to bed, staring at the ceiling of 227 00:17:33,690 --> 00:17:38,090 Speaker 1: his hotel room until the morning. Meanwhile, the rest of 228 00:17:38,130 --> 00:17:42,570 Speaker 1: the world was left to speculate. One popular theory was 229 00:17:42,570 --> 00:17:46,570 Speaker 1: that the skywalks were overcrowded with people dancing, and that 230 00:17:46,610 --> 00:17:50,770 Speaker 1: their rhythmic movements had set up dangerous resonances which destroyed 231 00:17:50,770 --> 00:17:54,850 Speaker 1: the structure. But the numbers didn't add up. The people 232 00:17:54,890 --> 00:17:57,490 Speaker 1: on the skywalks would have had to have been phrenetically 233 00:17:57,610 --> 00:18:01,650 Speaker 1: go go dancing, not gently nodding along to big band swing, 234 00:18:02,570 --> 00:18:05,450 Speaker 1: and the weight of the people was small compared with 235 00:18:05,490 --> 00:18:09,330 Speaker 1: the weight of the skywalks themselves. There were sixty three 236 00:18:09,370 --> 00:18:14,210 Speaker 1: people on walkways that, by coincidence, weighed sixty three tons. 237 00:18:15,370 --> 00:18:18,730 Speaker 1: Kansas City building codes demanded that the skywalks could have 238 00:18:18,770 --> 00:18:22,930 Speaker 1: carried nearly ten times as many people, more like five 239 00:18:23,010 --> 00:18:27,410 Speaker 1: hundred people than sixty three. Then talk turned to the 240 00:18:27,490 --> 00:18:31,370 Speaker 1: quality of construction, had someone tried to save money by 241 00:18:31,450 --> 00:18:38,290 Speaker 1: using cheap materials A reasonable guess, but no. Within days, 242 00:18:39,210 --> 00:18:43,490 Speaker 1: the world had figured out the skywalk's fatal flow thanks 243 00:18:43,530 --> 00:18:47,770 Speaker 1: to a young engineer, a telephoto lens, and the Kansas 244 00:18:47,770 --> 00:18:52,210 Speaker 1: City Star. I relied on reporting from the Kansas City 245 00:18:52,250 --> 00:18:55,770 Speaker 1: Star for the eyewitness accounts of the disaster, but the 246 00:18:55,810 --> 00:18:59,250 Speaker 1: newspaper also won a pull its surprise for its investigation 247 00:18:59,530 --> 00:19:05,050 Speaker 1: into exactly why the skywalks collapsed. After loud protests about 248 00:19:05,050 --> 00:19:07,810 Speaker 1: a cover up, the press were allowed to visit the 249 00:19:07,930 --> 00:19:13,210 Speaker 1: hyat's shattered atrium. The Star sent its best reporters and 250 00:19:13,330 --> 00:19:17,370 Speaker 1: at the last minute persuaded a young structural engineer named 251 00:19:17,490 --> 00:19:21,970 Speaker 1: Wayne Lishka to join them. The visit was a shock. 252 00:19:22,850 --> 00:19:26,130 Speaker 1: Wayne Lishke and his wife had spent evenings dancing in 253 00:19:26,170 --> 00:19:32,130 Speaker 1: the hotel lobby. The disaster seemed unnervingly close, but it 254 00:19:32,170 --> 00:19:36,170 Speaker 1: was also frustrating. Journalists were only allowed the view that 255 00:19:36,250 --> 00:19:39,770 Speaker 1: the hostess, Cindy Paulson, had had looking down at the 256 00:19:39,810 --> 00:19:43,690 Speaker 1: lobby floor from the elevated restaurant. It wasn't close enough 257 00:19:43,730 --> 00:19:48,050 Speaker 1: to see March, unless, of course, Lishka asked the Stars 258 00:19:48,090 --> 00:19:52,810 Speaker 1: photographer to use a long zoom lens even from a distance, 259 00:19:53,130 --> 00:19:55,770 Speaker 1: Lishka could point out the details he wanted to see 260 00:19:55,890 --> 00:20:00,450 Speaker 1: up close. Take a shot of that, he said, and 261 00:20:00,490 --> 00:20:06,850 Speaker 1: that and that. When the photographs were developed, they showed 262 00:20:06,890 --> 00:20:10,650 Speaker 1: the end of the vertical rods uselessly hanging from the 263 00:20:10,690 --> 00:20:15,050 Speaker 1: ceiling down to the fourth floor. Lishka could see clearly 264 00:20:15,410 --> 00:20:19,570 Speaker 1: that the rods were basically undamaged. They hadn't thinned or stretched. 265 00:20:20,650 --> 00:20:26,210 Speaker 1: The rods hadn't failed the skywalks had fallen off them. 266 00:20:26,730 --> 00:20:30,290 Speaker 1: Examining a few more photographs, Lishka and the Kansas City 267 00:20:30,370 --> 00:20:33,810 Speaker 1: Star had their answer, and on the front page of 268 00:20:33,850 --> 00:20:38,730 Speaker 1: the newspaper they published technical drawings highlighting a tiny detail 269 00:20:38,810 --> 00:20:42,730 Speaker 1: of the design, a tiny detail that had been overlooked 270 00:20:43,050 --> 00:20:48,770 Speaker 1: with the most appalling consequences. The detail concerned the connection 271 00:20:48,970 --> 00:20:52,930 Speaker 1: between the long vertical rods and the horizontal beams that 272 00:20:53,010 --> 00:20:58,130 Speaker 1: supported the walkways. These steel beams were hollow, big square 273 00:20:58,170 --> 00:21:03,290 Speaker 1: steel pipes. The vertical rods pierced each horizontal beam, and 274 00:21:03,330 --> 00:21:07,130 Speaker 1: the beam was supported by a steel nut threaded onto 275 00:21:07,170 --> 00:21:11,010 Speaker 1: each rod. The beam wouldn't slide down the rod because 276 00:21:11,170 --> 00:21:14,410 Speaker 1: the nut was in the way. That might sound flimsy, 277 00:21:14,450 --> 00:21:17,810 Speaker 1: but in fact, a well designed steel nut could support 278 00:21:17,890 --> 00:21:23,970 Speaker 1: a huge weight. Now Here comes the fatal detail. The 279 00:21:24,050 --> 00:21:28,330 Speaker 1: original drawings for the skywalks showed both of them suspended 280 00:21:28,370 --> 00:21:32,730 Speaker 1: from the same long rods. The fourth floor skywalk was 281 00:21:32,770 --> 00:21:35,930 Speaker 1: supported by nuts halfway up each rod, and the second 282 00:21:35,970 --> 00:21:39,010 Speaker 1: floor skywalk was fixed by nuts at the bottom of 283 00:21:39,050 --> 00:21:43,610 Speaker 1: the same rods. But that is not what was built. 284 00:21:45,130 --> 00:21:48,810 Speaker 1: Instead of hanging from the same long steel rods, the 285 00:21:48,970 --> 00:21:53,450 Speaker 1: upper skywalk hung from shorter rods, and the lower skywalk 286 00:21:53,650 --> 00:21:56,730 Speaker 1: hung from rods which were attached to the upper one. 287 00:21:57,210 --> 00:22:00,810 Speaker 1: Describing it, that change seems trivial, and if I were 288 00:22:00,810 --> 00:22:03,370 Speaker 1: to show you a technical drawing, the chances are you'd 289 00:22:03,410 --> 00:22:06,850 Speaker 1: still say that the change was trivial. It seems hard 290 00:22:06,930 --> 00:22:14,490 Speaker 1: to see why the change makes a difference. So picture this. 291 00:22:15,370 --> 00:22:18,130 Speaker 1: Imagine that you and a friend are planning to swing 292 00:22:18,210 --> 00:22:21,730 Speaker 1: on a rope hanging from a high tree branch. You'll 293 00:22:21,770 --> 00:22:23,450 Speaker 1: hold on to a knot in the middle of the 294 00:22:23,530 --> 00:22:25,810 Speaker 1: rope and your friend will hold on to a knot 295 00:22:25,890 --> 00:22:29,530 Speaker 1: near the bottom. But then you realize you don't have 296 00:22:29,570 --> 00:22:31,970 Speaker 1: a long enough piece of rope. You've only got two 297 00:22:32,050 --> 00:22:36,650 Speaker 1: shorter lengths. No problem, says your friend. She ties one 298 00:22:36,730 --> 00:22:39,610 Speaker 1: length of rope knotted at the bottom around the tree branch. 299 00:22:40,370 --> 00:22:43,930 Speaker 1: You swing from that rope, she says. Then she ties 300 00:22:44,010 --> 00:22:48,290 Speaker 1: the other length firmly around your waist. I'll swing from 301 00:22:48,290 --> 00:22:52,730 Speaker 1: this one. That isn't going to work, is it. Your 302 00:22:52,730 --> 00:22:55,770 Speaker 1: grip was strong enough to support your own weight, but 303 00:22:56,010 --> 00:22:58,930 Speaker 1: it's not strong enough to support both of you. It 304 00:22:58,970 --> 00:23:02,530 Speaker 1: won't be long before your clasped hands lose their grip, 305 00:23:02,810 --> 00:23:06,370 Speaker 1: slipping around the knot, and because your friend is hanging 306 00:23:06,370 --> 00:23:11,850 Speaker 1: from a rope attached to you, when you've shield fall. Two, 307 00:23:12,410 --> 00:23:16,290 Speaker 1: The apparently trivial design change to the skywalks had the 308 00:23:16,330 --> 00:23:21,290 Speaker 1: same fatal effect. Instead of two walkways hanging from the 309 00:23:21,330 --> 00:23:25,290 Speaker 1: same set of rods, now the upper walkway was supporting 310 00:23:25,290 --> 00:23:29,650 Speaker 1: its own weight and the weight of the lower skywalk two. 311 00:23:30,650 --> 00:23:34,970 Speaker 1: For a year, the steel strained under double the intended weight, 312 00:23:35,690 --> 00:23:40,370 Speaker 1: absolutely at the limit. What makes this an engineering tragedy 313 00:23:40,890 --> 00:23:45,770 Speaker 1: rather than an engineering curiosity was how finely balanced the 314 00:23:45,810 --> 00:23:51,130 Speaker 1: skywalks were. Any weaker than they would have collapsed during construction, 315 00:23:52,130 --> 00:23:56,770 Speaker 1: any stronger than they might have lasted indefinitely, but they 316 00:23:56,770 --> 00:24:01,330 Speaker 1: were just strong enough to stay aloft until one busy, 317 00:24:01,570 --> 00:24:05,530 Speaker 1: buzzing Friday evening in the summer of eighty one, when 318 00:24:05,810 --> 00:24:10,130 Speaker 1: hundreds of people danced underneath the skywalks, and a few 319 00:24:10,210 --> 00:24:18,170 Speaker 1: dozen more came to stand on them and watch. The 320 00:24:18,210 --> 00:24:22,450 Speaker 1: first responders to the disaster were weeping in frustration as 321 00:24:22,490 --> 00:24:26,530 Speaker 1: they tried to pry up the huge concrete slabs. People 322 00:24:26,610 --> 00:24:30,370 Speaker 1: underneath were begging for help, but the standard rescue equipment 323 00:24:30,570 --> 00:24:34,650 Speaker 1: was all but useless. As the words spread across Kansas 324 00:24:34,690 --> 00:24:38,090 Speaker 1: City of what was happening at the Hiat, construction workers 325 00:24:38,090 --> 00:24:41,410 Speaker 1: began to arrive at the site, bringing jackhammers and oxyo 326 00:24:41,450 --> 00:24:46,970 Speaker 1: settlin torches, portable generators and lights. The deputy fire chief 327 00:24:47,130 --> 00:24:50,210 Speaker 1: used to work part time at a construction crane operator 328 00:24:50,410 --> 00:24:53,810 Speaker 1: just down the street. He made the call, and before long, 329 00:24:54,130 --> 00:24:57,810 Speaker 1: the huge cranes were on their way to the scene. 330 00:24:58,210 --> 00:25:03,090 Speaker 1: Cindy Paulson was outside, still looking for her father, when 331 00:25:03,250 --> 00:25:07,450 Speaker 1: across the chaos she saw her mother instead. The two 332 00:25:07,570 --> 00:25:11,610 Speaker 1: rushed towards one another. How did you get here, asked Cindy, 333 00:25:12,650 --> 00:25:18,250 Speaker 1: Your father called her mother replied he was perfectly safe. 334 00:25:18,490 --> 00:25:22,130 Speaker 1: He'd left the hotel before the skywalks fell and only 335 00:25:22,170 --> 00:25:25,370 Speaker 1: heard about the accident on the radio. He'd called home 336 00:25:25,450 --> 00:25:28,250 Speaker 1: to reassure his family and Cindy's mother had rushed to 337 00:25:28,290 --> 00:25:31,930 Speaker 1: the scene to reassure Cindy. Cindy told her mother to 338 00:25:32,010 --> 00:25:35,730 Speaker 1: head home without her, she was going back in to help. 339 00:25:37,450 --> 00:25:41,010 Speaker 1: From time to time, Dr Wackerley would whistle as a 340 00:25:41,050 --> 00:25:45,050 Speaker 1: signal for the rescue effort to fall silent. The rescuers, 341 00:25:45,450 --> 00:25:49,810 Speaker 1: hundreds of them, would listen as trapped people called out 342 00:25:49,810 --> 00:25:53,650 Speaker 1: their names from under the rubble. The rescuers did their 343 00:25:53,650 --> 00:25:58,370 Speaker 1: best to mark the location of each one. After the 344 00:25:58,410 --> 00:26:02,930 Speaker 1: first hour or so, there wasn't much good news. Most 345 00:26:02,970 --> 00:26:06,170 Speaker 1: of the survivors were out. Most of those who remained 346 00:26:06,650 --> 00:26:11,050 Speaker 1: were beyond help, but there was the occasional moment to 347 00:26:11,130 --> 00:26:14,770 Speaker 1: lift the spirits. At two o'clock in the morning, a man, 348 00:26:15,010 --> 00:26:18,370 Speaker 1: a woman, and a boy were pulled alive from an 349 00:26:18,410 --> 00:26:23,730 Speaker 1: air pocket under the wreckage. Mark Williams, his legs wrenched 350 00:26:23,770 --> 00:26:28,730 Speaker 1: around his ears, was still waiting. The water around him 351 00:26:28,810 --> 00:26:33,210 Speaker 1: had receded, but the voices of those buried nearby had 352 00:26:33,290 --> 00:26:39,130 Speaker 1: also fallen silent. At three in the morning, two massive 353 00:26:39,170 --> 00:26:44,130 Speaker 1: cranes smashed through the atrium's beautiful glass wall, showering the 354 00:26:44,170 --> 00:26:46,690 Speaker 1: shards across the blood and the dust on the floor. 355 00:26:47,570 --> 00:26:51,690 Speaker 1: Those all two heavy concrete slabs were lifted a little, 356 00:26:52,090 --> 00:26:56,890 Speaker 1: letting rescuers call in and shine their torches. The excited 357 00:26:56,930 --> 00:27:01,170 Speaker 1: rescuers were now very close to Mark Williams, which posed 358 00:27:01,410 --> 00:27:06,170 Speaker 1: new and unexpected risks. He could hear a jackhammer getting 359 00:27:06,250 --> 00:27:11,530 Speaker 1: ever closer. Its chisel tip his ribs, then stabbed down 360 00:27:11,650 --> 00:27:15,530 Speaker 1: near his cross. Shut the jackhammer off, you idiots, he 361 00:27:15,650 --> 00:27:20,490 Speaker 1: yelled during a brief pause. They did, and a few 362 00:27:20,530 --> 00:27:25,330 Speaker 1: minutes later Mark Williams, twisted like a pretzel, but very 363 00:27:25,410 --> 00:27:30,170 Speaker 1: much alive, was pulled out of the rubble. After that, 364 00:27:30,650 --> 00:27:35,090 Speaker 1: there would be no more miracles. The rescuers had spent 365 00:27:35,250 --> 00:27:38,650 Speaker 1: the night cutting through dead bodies to reach the living, 366 00:27:39,050 --> 00:27:43,170 Speaker 1: trying to stabilize people with catastrophic injuries, digging out the 367 00:27:43,250 --> 00:27:48,970 Speaker 1: spouses who died together as they danced, eighteen married couples, 368 00:27:50,050 --> 00:27:54,010 Speaker 1: and finding the body of eleven year old Pamela Coffee, 369 00:27:54,250 --> 00:28:00,050 Speaker 1: the only child to die in the collapse. Dawn had 370 00:28:00,050 --> 00:28:04,970 Speaker 1: broken when the cranes lifted the final fallen section of skywalk. 371 00:28:05,890 --> 00:28:08,530 Speaker 1: For some of the rescuers, it was the moment when 372 00:28:08,530 --> 00:28:12,570 Speaker 1: the long struggle became too much to bear. There were 373 00:28:12,650 --> 00:28:27,850 Speaker 1: thirty one people underneath, every single one of them was dead. 374 00:28:29,650 --> 00:28:33,770 Speaker 1: Over the years, engineers have found a horrid fascination in 375 00:28:33,850 --> 00:28:37,210 Speaker 1: the skywalk collapse. It's been a case study in a 376 00:28:37,330 --> 00:28:42,010 Speaker 1: thousand engineering classes, a kind of logic puzzle. Spot the 377 00:28:42,050 --> 00:28:46,050 Speaker 1: floor in the innocuous, seeming design change. It's because the 378 00:28:46,170 --> 00:28:49,850 Speaker 1: error is so surprising, so easy to overlook, and then 379 00:28:50,090 --> 00:28:54,970 Speaker 1: so obvious in hindsight. Letting the lower skywalk hang off 380 00:28:54,970 --> 00:29:00,330 Speaker 1: the upper skywalk was the simple fatal error, so clear 381 00:29:00,570 --> 00:29:03,770 Speaker 1: only when you imagine swinging off a rope and trying 382 00:29:03,770 --> 00:29:07,010 Speaker 1: to bear the weight of someone swinging off you. The 383 00:29:07,050 --> 00:29:10,970 Speaker 1: steel crossbeams couldn't bear the double weight focused to that 384 00:29:11,250 --> 00:29:14,970 Speaker 1: small nut on the steel rod. The beams buckled and 385 00:29:15,090 --> 00:29:18,890 Speaker 1: slipped around the nut and off the rods, and disaster 386 00:29:19,050 --> 00:29:27,650 Speaker 1: followed almost instantly. After the tragedy, there was plenty of 387 00:29:27,690 --> 00:29:30,570 Speaker 1: commentary in places such as the letters page of the 388 00:29:30,770 --> 00:29:34,250 Speaker 1: Engineering News Record. Some pointed out that it was no 389 00:29:34,370 --> 00:29:38,490 Speaker 1: surprise that the original design concept had been modified. That 390 00:29:38,690 --> 00:29:42,930 Speaker 1: concept secured the upper skywalk by resting it on nuts 391 00:29:43,050 --> 00:29:47,730 Speaker 1: halfway up the vertical steel rods. Simple until you think 392 00:29:47,770 --> 00:29:52,050 Speaker 1: about it. How does each nut get there? One possibility 393 00:29:52,130 --> 00:29:55,090 Speaker 1: is to machine fifteen feet of each rod with a 394 00:29:55,170 --> 00:29:59,090 Speaker 1: fine screw thread and hope that those threads remain undamaged 395 00:29:59,330 --> 00:30:03,410 Speaker 1: while these six rods were installed in a busy construction site, 396 00:30:03,570 --> 00:30:07,450 Speaker 1: or perhaps custom made rods slightly slimmer at one end 397 00:30:07,530 --> 00:30:10,810 Speaker 1: than another, so that the nut can slide along until 398 00:30:10,810 --> 00:30:14,410 Speaker 1: it reaches the thread in the middle. There are other 399 00:30:14,490 --> 00:30:16,370 Speaker 1: ways to get a nut onto the middle of a 400 00:30:16,410 --> 00:30:20,650 Speaker 1: long rod, but the original design doesn't acknowledge that there's 401 00:30:20,810 --> 00:30:25,930 Speaker 1: even an issue. No wonder the contractor suggested a change. 402 00:30:25,970 --> 00:30:29,690 Speaker 1: As one engineer commented, a design that begs a change 403 00:30:30,210 --> 00:30:34,970 Speaker 1: cannot be completely without blame when the change is made. 404 00:30:35,130 --> 00:30:39,450 Speaker 1: The letter's page was filled with clever alternative solutions, but 405 00:30:39,850 --> 00:30:43,250 Speaker 1: it's not hard to find a solution once you clearly 406 00:30:43,370 --> 00:30:47,450 Speaker 1: understand that switching to an upper and lower rod posed 407 00:30:47,450 --> 00:30:53,130 Speaker 1: a problem in the first place. Nobody did I worry 408 00:30:53,170 --> 00:30:56,650 Speaker 1: that in focusing on the skywalk collapse as a flaw 409 00:30:56,770 --> 00:31:02,330 Speaker 1: in engineering design, we risk losing sight of the real problem. 410 00:31:02,650 --> 00:31:06,490 Speaker 1: Engineers will forevermore pay close attention to the design of 411 00:31:06,650 --> 00:31:11,410 Speaker 1: rod girder connections, But this isn't really about the structure 412 00:31:11,490 --> 00:31:16,050 Speaker 1: of a steel connection. It's about the structure of a project. 413 00:31:17,210 --> 00:31:21,530 Speaker 1: What failed wasn't just a beam. What failed was a 414 00:31:21,610 --> 00:31:27,050 Speaker 1: process turn away from the powerful eyewitness reporting of the 415 00:31:27,170 --> 00:31:31,490 Speaker 1: Kansas City Star and pick up instead a special May 416 00:31:31,570 --> 00:31:36,690 Speaker 1: two thousand symposium in the Journal of Performance of Constructed Facilities. 417 00:31:37,490 --> 00:31:43,090 Speaker 1: In that symposium, numerous engineers, including Jack Gillum himself, analyze 418 00:31:43,090 --> 00:31:48,690 Speaker 1: what went wrong. Gillum listed seventeen different factors contributing to 419 00:31:48,730 --> 00:31:52,690 Speaker 1: the error. The project was rushed, details weren't checked by 420 00:31:52,730 --> 00:31:57,970 Speaker 1: external reviewers, Senior people resigned from the engineering company halfway through, 421 00:31:58,490 --> 00:32:04,370 Speaker 1: important jobs were outsourced. Gillum himself protested that we requested 422 00:32:04,570 --> 00:32:09,530 Speaker 1: from the architect, owner and construction manager on three separate occads, 423 00:32:09,810 --> 00:32:13,410 Speaker 1: that we be permitted to provide full time inspection during 424 00:32:13,450 --> 00:32:18,170 Speaker 1: the construction, yet each time we were denied. Of course 425 00:32:18,530 --> 00:32:21,690 Speaker 1: Gillan was pleading his own case there, but the overall 426 00:32:21,770 --> 00:32:26,490 Speaker 1: impression is clear. It was a complicated project with lots 427 00:32:26,530 --> 00:32:29,090 Speaker 1: of ins and outs, lots of people coming and going. 428 00:32:29,850 --> 00:32:33,530 Speaker 1: It's easy to see how things could get missed. What's 429 00:32:33,650 --> 00:32:38,250 Speaker 1: unnerving about this is that, well, every big building is 430 00:32:38,290 --> 00:32:42,290 Speaker 1: a complicated project. We have to trust the project managers 431 00:32:42,530 --> 00:32:47,890 Speaker 1: to cope. In his book The Checklist Manifesto, The Surgeon 432 00:32:47,930 --> 00:32:51,490 Speaker 1: at All Gowande looks at how to prevent accidents in 433 00:32:51,570 --> 00:32:56,250 Speaker 1: modern medicine. It's all so complicated these days, he argues, 434 00:32:56,570 --> 00:33:00,650 Speaker 1: there are large medical teams, complex medical procedures, lots of 435 00:33:00,690 --> 00:33:03,570 Speaker 1: ways in which things can go wrong, often because of 436 00:33:03,610 --> 00:33:08,050 Speaker 1: a simple oversight. Gonde makes a compelling case that this 437 00:33:08,250 --> 00:33:12,930 Speaker 1: complexity can be tamed with checklists, agree a list of 438 00:33:12,970 --> 00:33:16,010 Speaker 1: what has to be done, everything from a surgical team 439 00:33:16,170 --> 00:33:19,090 Speaker 1: introducing themselves to each other, to ensuring that there are 440 00:33:19,130 --> 00:33:22,370 Speaker 1: the right supplies and spares on hand, to making sure 441 00:33:22,570 --> 00:33:25,530 Speaker 1: that you have the right patient on the operating table 442 00:33:25,570 --> 00:33:30,690 Speaker 1: in front of you. Checklists sound absurdly simple, but in 443 00:33:30,730 --> 00:33:35,410 Speaker 1: many cases they've been proved to work. But what's striking 444 00:33:35,450 --> 00:33:39,290 Speaker 1: to me is where Atulgoande originally got the inspiration for 445 00:33:39,330 --> 00:33:42,970 Speaker 1: this idea. It was talking to the team who were 446 00:33:43,010 --> 00:33:47,290 Speaker 1: building an eleven story extension to the hospital where he worked. 447 00:33:48,930 --> 00:33:52,130 Speaker 1: Three thousand, eight hundred and eighty five tons of steel, 448 00:33:52,930 --> 00:33:57,810 Speaker 1: thirteen thousand cubic yards of concrete, nineteen air handling units, 449 00:33:58,370 --> 00:34:04,490 Speaker 1: sixteen elevators, one cooling tower, and one back up emergency generator, 450 00:34:05,610 --> 00:34:09,690 Speaker 1: and to make sure nothing was missed. Checklists, lots of checklists. 451 00:34:10,290 --> 00:34:15,290 Speaker 1: Checklists for schedules, checklists for communication, checklists for checklists. But 452 00:34:15,450 --> 00:34:18,610 Speaker 1: when it came to building the highatt regency in Kansas City, 453 00:34:19,330 --> 00:34:25,210 Speaker 1: some vital boxes never got ticked. There's one pivotal moment 454 00:34:25,530 --> 00:34:30,770 Speaker 1: worth highlighting. It happened early in January nineteen seventy nine, 455 00:34:30,810 --> 00:34:34,730 Speaker 1: two and a half years before the disaster. At the time, 456 00:34:34,970 --> 00:34:39,010 Speaker 1: it didn't seem like much, and that was the problem. 457 00:34:39,210 --> 00:34:41,930 Speaker 1: It was simply a phone call, which was a common 458 00:34:42,010 --> 00:34:45,330 Speaker 1: enough way of communicating in the days before email. A 459 00:34:45,410 --> 00:34:49,810 Speaker 1: manager at the steel fabricator phoned the structural engineer's project 460 00:34:49,810 --> 00:34:53,970 Speaker 1: manager and suggested that fateful switch from the long single 461 00:34:54,090 --> 00:34:58,290 Speaker 1: rods to the shorter pairs of rods. The structural engineer 462 00:34:58,450 --> 00:35:01,610 Speaker 1: thought it through while still on the phone, but missed 463 00:35:01,650 --> 00:35:05,490 Speaker 1: the critical realization that the change would double the load 464 00:35:05,810 --> 00:35:08,850 Speaker 1: that the upper beams were supporting. He said that the 465 00:35:08,890 --> 00:35:13,450 Speaker 1: check change sounded fine, but asked the steel fabricator to 466 00:35:13,530 --> 00:35:20,850 Speaker 1: submit the request through formal channels. That formal request was 467 00:35:20,890 --> 00:35:27,250 Speaker 1: never made. Do you see why I say this was 468 00:35:27,330 --> 00:35:30,730 Speaker 1: a process error as much as a failure of structural 469 00:35:30,850 --> 00:35:34,770 Speaker 1: engineering design. Someone makes a phone call with a request, 470 00:35:35,290 --> 00:35:38,730 Speaker 1: someone else says it sounds okay, but put it in writing. 471 00:35:39,370 --> 00:35:44,530 Speaker 1: It never gets put in writing. Nobody follows up. This 472 00:35:44,610 --> 00:35:47,650 Speaker 1: sort of thing happens all the time in offices all 473 00:35:47,650 --> 00:35:52,130 Speaker 1: over the world. Meeting notes are unclear or nonexistent, or 474 00:35:52,170 --> 00:35:57,410 Speaker 1: lost emails disappear down into the depths of an overloaded inbox. 475 00:35:58,250 --> 00:36:00,930 Speaker 1: People agree that some task needs to be done, but 476 00:36:01,090 --> 00:36:04,290 Speaker 1: it's not quite clear who's responsible, and so in the 477 00:36:04,410 --> 00:36:09,290 Speaker 1: end nobody is. We've all seen it happen. It's just 478 00:36:09,330 --> 00:36:12,570 Speaker 1: that usually when someone's a bit sloppy with their to 479 00:36:12,610 --> 00:36:19,450 Speaker 1: do list, nobody dies. This time, people did, a lot 480 00:36:19,450 --> 00:36:25,410 Speaker 1: of people. Jack Gillum, the structural engineer with overall responsibility 481 00:36:25,410 --> 00:36:30,210 Speaker 1: for the project, explained the connection that failed was never designed. 482 00:36:30,890 --> 00:36:33,810 Speaker 1: The original detail of the connection as shown on the 483 00:36:33,850 --> 00:36:39,010 Speaker 1: contract structural drawings was only conceptual in nature. Neither the 484 00:36:39,090 --> 00:36:43,530 Speaker 1: original detail nor the double rod connection as built was designed, 485 00:36:44,290 --> 00:36:48,810 Speaker 1: so not a failure of design, an absence of design 486 00:36:49,970 --> 00:36:55,450 Speaker 1: because of a failure of process. When the official investigation 487 00:36:55,730 --> 00:37:00,250 Speaker 1: was completed by the National Bureau of Standards, it concluded that, yes, 488 00:37:00,690 --> 00:37:04,010 Speaker 1: the switch from long single rods to short double rods 489 00:37:04,490 --> 00:37:07,930 Speaker 1: was probably the difference between the skywalks staying up and 490 00:37:07,970 --> 00:37:12,130 Speaker 1: the skywalks falling. But it also concluded that even the 491 00:37:12,170 --> 00:37:15,690 Speaker 1: original design wasn't strong enough to meet the requirements of 492 00:37:15,850 --> 00:37:20,370 Speaker 1: Kansas City's building code. The original design would almost certainly 493 00:37:20,410 --> 00:37:23,650 Speaker 1: not have collapsed, which of course is the important thing, 494 00:37:24,130 --> 00:37:28,130 Speaker 1: But the original design was still too weak. Nobody ever, 495 00:37:28,170 --> 00:37:32,330 Speaker 1: seems to have checked that, and nobody had noticed, not 496 00:37:32,410 --> 00:37:37,210 Speaker 1: the structural engineers, not the steel fabricators, not the building inspectors. 497 00:37:38,690 --> 00:37:42,450 Speaker 1: In the arguments and legal disputes that followed, the attorney 498 00:37:42,570 --> 00:37:46,290 Speaker 1: representing the state Licensing Board said it wasn't a matter 499 00:37:46,370 --> 00:37:50,090 Speaker 1: of doing something wrong, They just never did it at all. 500 00:37:51,490 --> 00:37:55,010 Speaker 1: Nobody ever did any calculations to figure out whether or 501 00:37:55,130 --> 00:37:58,370 Speaker 1: not the particular connection that held the sky walks up 502 00:37:58,610 --> 00:38:03,170 Speaker 1: would work. It got built without anybody ever figuring out 503 00:38:03,210 --> 00:38:06,850 Speaker 1: if it would be strong enough. It just slipped through 504 00:38:06,850 --> 00:38:12,450 Speaker 1: the cracks literally true, of course, under the tremendous weight 505 00:38:12,490 --> 00:38:16,490 Speaker 1: of two skywalks. The nut ripped through the weakest point 506 00:38:16,530 --> 00:38:19,890 Speaker 1: of the box beams, a welding scene that cracked open 507 00:38:20,690 --> 00:38:24,410 Speaker 1: metaphorically true as well. In between the tooing and throwing, 508 00:38:24,650 --> 00:38:29,650 Speaker 1: the resignations, and the outsourcing, everyone assumed that someone had 509 00:38:29,690 --> 00:38:36,410 Speaker 1: designed and checked the steel joint, nobody had it slipped 510 00:38:36,690 --> 00:38:42,490 Speaker 1: through the cracks. One hundred and fourteen people died in 511 00:38:42,530 --> 00:38:48,210 Speaker 1: the disaster, almost two hundred were injured. No criminal charges 512 00:38:48,290 --> 00:38:51,650 Speaker 1: were filed, but Jack Gillum and one of his colleagues 513 00:38:51,810 --> 00:38:55,890 Speaker 1: lost their license to practice in Missouri. Gillam spent his 514 00:38:55,970 --> 00:38:59,530 Speaker 1: twilight years retelling the story of the collapse as a 515 00:38:59,650 --> 00:39:04,770 Speaker 1: cautionary tale for other construction professionals. He often spoke to 516 00:39:04,890 --> 00:39:08,690 Speaker 1: engineers about the disaster, hoping to scare the daylights out 517 00:39:08,690 --> 00:39:13,090 Speaker 1: of them. The buck stops with me, he would tell them, 518 00:39:13,370 --> 00:39:19,090 Speaker 1: that was my engineering seal on the plans. Student hostess 519 00:39:19,210 --> 00:39:23,090 Speaker 1: Cindy Paulson spent that night at the hyat helping with 520 00:39:23,130 --> 00:39:27,570 Speaker 1: the rescue effort. It took a toll on her her grades. 521 00:39:27,810 --> 00:39:31,770 Speaker 1: Once outstanding started to fall, she took time out of 522 00:39:31,770 --> 00:39:35,130 Speaker 1: her studies to try to reset, but that didn't help either. 523 00:39:36,050 --> 00:39:39,610 Speaker 1: She was later diagnosed with depression, but she got on 524 00:39:39,690 --> 00:39:43,090 Speaker 1: with life and found a career selling real estate. She 525 00:39:43,210 --> 00:39:46,090 Speaker 1: tries not to think too much about the hyat, but 526 00:39:46,250 --> 00:39:51,370 Speaker 1: she can't help but get nervous on walkways. Mark Williams, 527 00:39:51,810 --> 00:39:54,450 Speaker 1: the last person to be pulled out of the rubble alive, 528 00:39:55,010 --> 00:39:58,650 Speaker 1: spent two months in hospital, much of it on dialysis 529 00:39:58,690 --> 00:40:01,770 Speaker 1: because his kidneys had given up under the strain. He 530 00:40:01,850 --> 00:40:05,170 Speaker 1: spent a further two years learning to walk again, a 531 00:40:05,170 --> 00:40:10,570 Speaker 1: little unevenly, but not too bad. He gave an upbeat 532 00:40:10,610 --> 00:40:14,410 Speaker 1: assessment to The Kansas City Star. We don't know what 533 00:40:14,530 --> 00:40:19,050 Speaker 1: we can accomplish, what we can withstand until we're tested. 534 00:40:20,210 --> 00:40:23,770 Speaker 1: As a slogan for life, it's a good one, but 535 00:40:23,850 --> 00:40:26,930 Speaker 1: it was never supposed to be a principle of engineering design. 536 00:40:27,850 --> 00:40:31,050 Speaker 1: We rely on engineers to get things right on the 537 00:40:31,130 --> 00:40:35,050 Speaker 1: drawing board. We don't expect to find out the hard 538 00:40:35,090 --> 00:40:39,930 Speaker 1: way that sixty tons of steel and concrete are floating 539 00:40:39,970 --> 00:40:44,810 Speaker 1: in the sky on a joint that nobody designed and 540 00:40:44,850 --> 00:41:10,170 Speaker 1: nobody checked. A key source for this episode was Donna 541 00:41:10,250 --> 00:41:13,810 Speaker 1: McGuire's reporting for The Kansas City Star in two thousand 542 00:41:13,850 --> 00:41:17,170 Speaker 1: and one. For a full list of references, check out 543 00:41:17,170 --> 00:41:24,690 Speaker 1: the show notes. It's Timharford dot com. Cautionary Tales is 544 00:41:24,690 --> 00:41:28,810 Speaker 1: written by me Tim Harford with Andrew Wright. It's produced 545 00:41:28,810 --> 00:41:32,850 Speaker 1: by Ryan Dilly with support from Courtney Garino and Emily Vaughan. 546 00:41:33,330 --> 00:41:36,490 Speaker 1: The sound design and original music is the work of 547 00:41:36,530 --> 00:41:41,570 Speaker 1: Pascal Wise, Julia Barton edited the scripts. It features the 548 00:41:41,650 --> 00:41:46,690 Speaker 1: voice talents of Ben Crowe, Melanie Gutteridge, Stella Harford, and 549 00:41:46,810 --> 00:41:50,690 Speaker 1: rufus Wright. The show also wouldn't have been possible without 550 00:41:50,730 --> 00:41:55,530 Speaker 1: the work of Mea LaBelle, Jacob Weisberg, Heather Faine, John Schnaz, 551 00:41:56,090 --> 00:42:03,130 Speaker 1: Carli Migliori, Eric Sandler, Royston Basserv Maggie Taylor, Nicolmrano, Daniela Lakhan, 552 00:42:03,490 --> 00:42:08,330 Speaker 1: and Maya Kanigg. Cautionary Tales is a production of Pushkin Industries. 553 00:42:08,690 --> 00:42:11,450 Speaker 1: If you like the show, please remember to share, rate 554 00:42:11,650 --> 00:42:14,090 Speaker 1: and review, and if you want to hear the show, 555 00:42:14,210 --> 00:42:18,410 Speaker 1: add free and listen to four exclusive Cautionary Tale shorts. 556 00:42:18,850 --> 00:42:21,610 Speaker 1: Then sign up for Pushkin Plus on the show page 557 00:42:21,730 --> 00:42:27,450 Speaker 1: in Apple Podcasts or at pushkin dot fm, slash plus