On the evening of Friday, July 17, 1981, between 1,500 and 2,000 people filled the atrium of the Hyatt Regency in Kansas City for a dance. The hotel was about a year old. Three walkways hung over the lobby from the atrium roof, and people stood on them to watch. At 7:04, according to newspaper accounts that federal investigators compiled, the band came back from its break to play for a dance contest. A minute later, the fourth-floor walkway and the second-floor walkway hanging beneath it fell to the lobby floor. Together they weighed 142,000 pounds. The last survivor was pulled from the debris at 4:30 the next morning. A Missouri appeals court later counted 114 dead and at least 186 injured.
The walkways hung from steel rods. Where each rod met a walkway’s beam there was a connection, and the court was plain about whose job those were: “All connections are the responsibility of the structural engineer.” By custom, a structural engineer may leave the design of connections to the steel fabricator, but has to show that on the drawings.
That is where the work went missing. The project engineer at the structural engineering firm, G.C.E. International, testified that he had intended the fabricator, Havens Steel, to design these connections. A state hearing commission found the drawings said the opposite: they told the fabricator the engineer had already designed them. Havens prepared its shop drawings on that basis. The engineer could have designed the connections or marked them for the fabricator to design. “These drawings did neither,” the court wrote.
Then the design changed. To solve a fabricating problem, Havens proposed hanging the second-floor walkway from the fourth-floor walkway with a second set of rods, instead of running one long rod through both. That doubled the load on the fourth-floor connections. A technician at the engineering firm raised questions about the rods and the change. The project engineer told the technician it was “basically the same as the one rod concept.” The firm approved the shop drawings. No review was made, the court found, and no calculations were performed to check whether the connection met the building code.
There was one more chance. During construction the atrium roof collapsed, and the owner had the engineers check the design of the whole atrium; the construction manager asked them specifically to inspect the steel in the walkways. Their report said, “we then checked the suspended bridges and found them to be satisfactory.” The court found they had checked only the roof steel.
The National Bureau of Standards found that even the original design would not have met the Kansas City building code. As built, the walkways “had only minimal capacity to resist their own weight.” In 1988 the appeals court upheld the revocation of the two engineers’ licenses and the firm’s. “Custom, practice, or ‘bottom line’ necessity,” it wrote, “cannot alter that responsibility.”