They Were Dancing When the Roof Fell

On Friday, July 17, 1981, between 1,500 and 2,000 people were dancing in the atrium of the Hyatt Regency Kansas City. At 7:05 PM, the fourth-floor skywalk failed. Sixty-four thousand pounds of concrete and steel fell forty feet onto the second-floor walkway. Then onto the dance floor. 114 people died. It remained the deadliest structural failure in American history for exactly twenty years and one month. It did not happen because of an earthquake or a bomb. It happened because two structural engineers approved a change to their own design over the phone — and never did the maths a second time. This is FILE 04 of THE ENGINEERING FILES — documentaries about the engineering decisions, structural failures, and ethical choices that shape the physical world. ▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬ CHAPTERS 0:00 — Cold open · 114 dead in an atrium 1:24 — The Hyatt Regency · Crown Center 1980 2:16 — The original design · A single continuous rod 3:23 — The phone call · Havens Steel proposes a change 5:27 — The warnings nobody heard 6:08 — 7:05 PM · Friday, July 17, 1981 7:54 — The Kansas City Star investigation · Wayne Lischka 8:37 — The trial · Gillum and Duncan lose their licences 9:32 — The legacy · why every engineer knows this story 10:59 — Coda ▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬ SOURCES · National Bureau of Standards — "Investigation of the Kansas City Hyatt Regency Walkways Collapse" (NBSIR 82-2465, May 1982) · Kansas City Star — Rick Atkinson investigative series (Nov 1981, Pulitzer 1982) · ASCE / Marshall, R.D. et al. — Engineering News-Record (Aug-Sep 1981) · State of Missouri v. Daniel M. Duncan and Jack D. Gillum — Administrative ruling 1986 · Robert L. Pfrang — "The Hyatt Disaster" — Journal of Construction Engineering and Management (1984) · Jack Gillum interview series — Penn State Engineering Ethics Library · "Engineering Disasters: Lessons to be Learned" — Don Lawson, 2005 ▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬ THE ENGINEERING FILES — case studies on the engineering decisions that shaped, and sometimes failed, the physical world. New files regularly. Subscribe so the next file finds you. #EngineeringDisaster #HyattRegency #StructuralEngineering #Documentary #EngineeringEthics