Hyatt Failure from the Perspective of a Forensic Engineer

The tragedy of this hotel atrium walkway collapse claimed 114 lives leading to a great public and professional outcry, and a dramatic impact on careers and lives of many fine professionals. The Architecture and Engineering (A&E) community in the United States began a soul-searching debate on issues as diverse as how project workflow is managed to professional responsibility and ethics. Fundamental errors were identified in the project interaction within the A&E group as well as the construction industry. As a result changes to the code of ethics and professional practice were introduced. Engineering issues of load, stress, and deformation are quite simple in the case of the walkway collapse. The issue of how much each of the inadequacies in the design and construction contributed to the tragic failure is significantly more complex. This review provides a presentation of the demand-capacity ratio associated with elements primary to the failure. Why did it take a year for the walkway's suspension system to fail? Results of detailed structural analysis, including inelastic finite element analysis of the box girder-to-hanger rod connection are discussed. Large inelastic deformations under the dead load alone are calculated. Why wasn't this desperately precarious condition noticed earlier? What were the safety margins of its individual components prior to the collapse? By how much could good construction practice and plain good old common sense have influenced these margins? In summary, the collapse occurred because of the doubling of the load on the connection resulting from ill-considered change of an ill-defined structural detail. However, this lesson on how any minor additional effort might have substantially improved the connection capacity, or even prevented the failure of the structure, should be studied and remembered.