The Hyatt Regency Skybridge Disaster

In 1981 two walkways collapsed in the lobby of the Hyatt Regency hotel in Kansas City. This disaster killed 114 people and injured 216. The main problem was a lack of communication between Jack D. Gillum and Associates and Havens Steel. This lack of communication occurred when Havens Steels used drawings that were created as preliminary sketches, as final designs. This led to a situation in which the second floor walkway was being supported by only the fourth floor walkway when it was originally meant to be supported by rods going up to the ceiling by passing through the fourth floor’s walkway beams. Changing this design caused the fourth floor walkway to have double the amount of force applied to it as it was originally supposed to.

Even before the change was made the design was still flawed with the design load of the rods being 90kN for each walkway which, in accordance with Kansas City Building Code, would have fallen short of the minimum value which should have been 151kN, meaning that the ultimate capacity was only around 60% of the required ultimate load capacity. When the designs were changed however, this was made even worse due to the design load on the fourth floor walkway being increased to 181kN. Below is an image demonstrating the differences between the original design and how the walkways were actually supported (image obtained from google images).

This lack of communication originated due to the lead engineer not having enough time to personally oversee the projects so they assigned tasks to associate engineers and then failed to properly follow up themselves. So a lesson to learn would be that if you are going to delegate tasks, you should always double check the calculations and you should always have someone double check yourself. When people’s lives are at stake there is no such thing as over analyzing. This disaster helps reinforce how serious it is to check the calculations on designs multiple times and to make sure that the calculations are correct before construction and for each calculation to be redone anytime there is a change in the design.

Sources

Berhardt, Randall. August, 2016. “Hyatt Regency Skywalk Collapse Remembered”. Structure Magazine. Accessed October 14th, 2020. https://www.structuremag.org/?p=10274

McFadden, Christopher. July 4, 2017. “Understanding the Tragic Hyatt Regency Walkway Collapse”. InterestingEngineering.com. Accessed October 14, 2020. https://interestingengineering.com/understanding-hyatt-regency-walkway-collapse

Munger, Paul. January, 2007. “The Hyatt Regency Walkway Collapse”. ASCE. Accessed October 14, 2020. https://www.asce.org/question-of-ethics-articles/jan-2007/

Staff posted. October 6, 2006. “Hyatt Regency Walkway Collapse”. Engineering.com. Accessed October 14, 2020. https://www.engineering.com/Library/ArticlesPage/tabid/85/articleType/ArticleView/ArticleID/175/PageID/199/Default.aspx