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How the Kansas City Hyatt Regency Walkway Collapse Changed the Engineering Profession

Date: 12 October 2018

When 1,600 people gathered at the tea dance held at the Kansas City Hyatt Regent hotel on Friday, July 17, 1981, they expected a joyful evening. They had no idea that the dance would end in tragedy, becoming one of the deadliest structural engineering failures in U.S. history. 

Credit: Command and Safety, FireEMSblogs, PennWell Corporation.


Spectators took in the festivities from the second-, third- and fourth-level walkways. At around 7:05 p.m., the fourth-level suddenly dropped from bearing the spectators’ weight before falling onto the second-floor walkway. Both the second-level and fourth-level walkways crashed to the lobby floor, killing 111 people and injuring 219. Three people died on the way to the hospital, bringing the final death tally to 114. 

The American Society of Civil Engineers (ASCE) declared the collapse “one of the most devastating structural failures in U.S. history in terms of lives lost.” It was the deadliest collapse until the World Trade Center towers crashed down on September 11, 2001. 

During the aftermath of the Hyatt Regency disaster, forensic engineers played a critical role investigating what caused the collapse. “When the engineers investigated the failure, they discovered a change to the original design of the walkways that was proposed by the fabricator and accidentally approved by the structural engineer,” says Tyler Gray, a principal recruitment consultant specialising in forensic architecture and forensic engineering at LVI Associates. 

Through onsite inspections, lab tests, and analytical studies, the forensic engineers determined the primary cause of the structural failure was a change from the original design to a double-rod system, resulting in one hanger rod connecting the ceiling to the upper walkway and the other connecting to the lower and upper walkways.  The modified design doubled the load the upper walkway and fell short of the minimum load required by Kansas City building codes. 

The Hyatt Regency disaster has become a case study in ethics and the ASCE still draws on the lessons. It was the forensic engineering work that uncovered the source of the failure was due to a communications breakdown. 

The ASCE describes forensic engineering as the application of engineering principles to the investigation of failures or other performance problems. Forensic engineers investigate failures and may provide expert testimony in civil or criminal court proceedings.

Today, forensic engineers play a critical role in ensuring the safety of people by analysing the structural soundness of buildings. “Throughout construction, they assess the potential for failures. They supply and implement design repairs,” explains Gray. 

Becoming a forensic engineer is a challenging but rewarding career. Forensic engineers often investigate catastrophic failures. Through the application of technical and scientific expertise, forensic engineers often perform reverse engineering to determine what caused the structural failure. 

Forensic engineers help to prevent future catastrophes. For instance, forensic engineers are still analysing the evidence gathered from London’s Grenfell Tower, a 24-storey residential tower devoured by fire on June 4, 2017, that resulted in 72 deaths. As with the aftermath of Hyatt Regency walkway collapse, the Grenfell Tower forensic engineers’ findings will result in better materials, engineering, and construction of new buildings. 

There is a high demand for forensic engineers and that demand will continue to grow. “There will always be structural design errors, there will always be natural disasters, and there will always be bad construction,” says Gray.