In 1981, a walkway in the Hyatt Regency Hotel in Kansas City collapsed, killing 114 people and injuring 200 more. A change in the original design of a series of walkways suspended above the lobby’s hotel led to a connection failure. The original design had all of the walkways suspended from the ceiling with steel rods retained by nuts. Even prior to the design change, the original design only supported 60% of the minimum load required by the Kansas City Building Code.
Fatal changes to the design caused the Hyatt Regency walkway collapse
The contractor responsible for manufacturing the steel rods objected to the use of threaded steel rods, as they felt the threads would be damaged during construction. They proposed an alternative plan where the lowest platform would be supported on one end by the ceiling, but on the other end by an upper level platform. This left the upper level 
platform, already under-designed, with a double load. The contractor claimed they did speak with the engineer over the telephone and he approved the change without viewing any drawings or performing any subsequent calculations. The engineering company maintains they did not receive a call and d
enied the change was approved. The change was a fatal flaw.
The engineers who had approved the final drawings were convicted by the Missouri Board of Architects, Professional Engineers and Land Surveyors of gross negligence, misconduct and unprofessional conduct in the practice of engineering. They lost their engineering licences in the states of Missouri, Kansas and Texas along with their membership with ASCE (American Society of Civil Engineers). Although the engineering company itself was not charged with criminal negligence, it lost its licence to be an engineering firm.
Introduction of new regulations
As the accident caused significant loss of life as well as substantial litigation and loss of revenue, engineering companies have made it a priority to manage the design life cycle to ensure that designs are safe, changes are evaluated, and risks are mitigated. Engineering programs allowing structural designs to be modelled, easily changed and re-verified for code compliance have made this process much simpler. Engineering companies currently require a licenced engineer to review and approve all shop drawings and require any changes to be drawn, submitted and approved.
While these changes have had a material impact on the safety of new engineering projects and helped to maintain a paper trail throughout the various processes, it all came too late for those who lost their lives on that fateful day.
