Hyatt 1981: The Walkways Could Barely Hold Their Own Weight

On 17 July 1981, two suspended walkways fell into the crowded atrium of the Hyatt Regency in Kansas City. 114 people died. The usual story blames one design change. The federal investigation says more: the walkways carried only about 63 people that night, the original connection was already only about 60 percent as strong as the building code required, and after the change the walkways could barely hold their own weight from the day they were built. This video follows the evidence the National Bureau of Standards followed: the videotape, the box-beam connection, the two-rod change and the stamped shop drawings, and 29 months of warnings, from a partial roof collapse to steel fitters refusing to work on the fourth-floor bridge. All figures come from NBS Building Science Series 143 (1982) and the sources below. Drawings and investigation photos are public-domain NBS/NARA records; illustrations are marked in the credits. 00:00 They weren't overloaded 00:31 Friday, 7:05 PM 02:19 Evidence 1: 63 people 03:47 Evidence 2: The connection 06:04 Evidence 3: The change 08:11 Evidence 4: 29 months of warnings 10:32 The verdict 12:34 Who owned the arithmetic tags: Hyatt Regency walkway collapse, Kansas City 1981, skywalk collapse, structural engineering failure, engineering disaster, box beam hanger rod, NBS nvestigation, engineering ethics, shop drawings, Jack Gillum, Havens Steel, building collapse documentary, structural failure explained