The collapse was caused by the failure of connections supporting the fourth-floor walkway ceiling rods. This walkway crashed onto the second-floor walkway directly beneath, which in its turn fell to the floor of the lobby.

The Hyatt Regency walkway collapse in Kansas City on July 17, 1981, was one of the deadliest structural failures in U.S. history, caused by a fatal and avoidable engineering design flaw. During construction, the original design for the hanging walkways was changed from a single-rod system to a double-rod system. In the original plan, a single continuous rod would have supported both the fourth and second-floor walkways. The revised plan used two separate rods, but this had the catastrophic effect of doubling the load on the nuts and beams of the upper (fourth-floor) walkway. Essentially, the fourth-floor supports were forced to carry the weight of both walkways and all the people on them simultaneously. The connections could only withstand about 30% of the required load, leading to the collapse when the walkways were crowded during a tea dance, resulting in 114 fatalities.