In the nation’s worst building collapse, a crowded walkway in the Kansas City Hyatt Regency Hotel failed in 1981, killing 114 people and injuring more than 200. NIST experts found that the design of critical connections in two walkways had been changed from the original plans and did not meet local building codes. Their findings led the American Society of Civil Engineers to adopt a document that for the first time assigned responsibility for various aspects of the construction process.