Some of the racier moments of my uneventful childhood occurred in the elementary school library, where we mayhem-hungry 8-year-old boys would often gather to watch an extraordinary little videotape of the 1940 Tacoma Narrows Bridge collapse in Washington state. Under the fairly ordinary force of a high wind, the thin, graceful suspension bridge bucked and writhed like an eel; then the suspension cables snapped and deranged sections of the span ripped themselves free and plunged into the water below. To us, it was as thrilling and mysterious as pornography.
The Tacoma Narrows disaster is one of many engineering fiascoes analyzed by Phillip Wearne in "Collapse: When Buildings Fall Down," the companion book to a Learning Channel TV series of the same name. On the surface, the book appeals directly to the mayhem-hungry 8-year-old in all of us. But what it's really about is the technical nitty-gritty of structures of all kinds -- how they're designed, built and inspected, and how oversights at any stage of the process can have terrible consequences.
Wearne focuses on collapses within living memory, calling on the testimony of witnesses, geological experts and, especially, forensic engineers, the experts who comb the rubble to figure out what went wrong. It's a fascinating and alarming survey. The Point Pleasant Bridge over the Ohio River collapsed in 1967, killing 46 people, because of a tiny flaw in a single piece of steel that had taken four decades to grow into a fatal crack. But that's a rarity among the incidents Wearne examines.
Sometimes the design was unsafe to begin with or was modified without proper safety checks during construction, like the catwalks over Kansas City's Hyatt Regency atrium that fell in 1981, killing 114. Sometimes structures were solid but the earth they were built on was not, as with the 1989 collapse of the Nimitz Freeway in Oakland, Calif., and the port of Kobe, Japan, in 1995. And sometimes the use of the structure had been modified, giving rise to load-bearing problems that were never anticipated by the architect -- like the Sampoong Superstore in Seoul, South Korea, originally designed as an office block, which was turned into a department store by way of suicidally reckless structural modifications. It collapsed in 1995, fatally squashing 498 people.
One of Wearne's case studies tells of a 22-story high-rise apartment block in England called Ronan Point, a hefty chunk of which fell down in 1968, 10 weeks after it was finished. A small gas explosion on the 18th floor blew out the walls of one outside room; the walls themselves were all that was holding up the floors above, and when the upper floors fell, they took out all the floors below. That's a basic design flaw, and a particularly scary one since it was used for a whole program of high-rises thrown up by the British government during this period. These buildings were shored up after the collapse, and Ronan Point was partly rebuilt, but as an added nightmare, Wearne reports, when Ronan Point was finally demolished in 1984, investigators looked at the very mortar of the building and found that it was intermixed with cigarette butts, tin cans and dust: The building was made of garbage.
Usually a building's problems are harder to pinpoint. When the Alfred P. Murrah Federal Building in Oklahoma City was blown up in 1995, the bomb directly took out only one support column, but there was no redundancy built into the load-bearing scheme, and a chain reaction of beam and column failures caused nearly half the building to disintegrate in seconds. It simply wasn't designed to resist a bomb. Wearne points out that unlike a car, a new building can't be crash-tested, so what happened in Oklahoma City provided invaluable guidance for future construction of government buildings. It also confirmed that many existing buildings would fare just as poorly if bombed.
Perhaps most astonishing is the tale of the Vaiont Dam, completed in 1960 in a gorge in Northern Italy. In 1963, a large section of mountainside broke off and slid into the dam's reservoir, sending most of the water over the top of the dam and down the valley in a wave hundreds of feet high. Several small towns were washed away, 2,043 people drowned ... and the dam itself remained intact. It was, Wearne writes, "a construction disaster without a structural failure -- a unique occurrence." There had been a smaller landslide during construction of the dam; a couple of geologists had warned the government strongly that the mountain was still unstable and had been rebuffed in their attempts to get the project scaled down.
What's so chilling about Wearne's book is that in a great many of the other collapses he describes, problems were similarly called to the builders' attention at some point and economics or bureaucratic laziness stymied corrective action. He makes you wonder why our homes and offices aren't always falling down around our ears. Or, rather, he instills in you a new admiration for all the architects, contractors and inspectors who do their work properly, so we don't usually have to think about them at all.