"He had no idea what he was doing," Jim D. Wiethorn, chairman and principal of Haag Engineering, tells ENR. Wiethorn discusses the collapse in the new book, "Crane Accidents: A Study of Causes & Trends To Create a Safer Work Environment," published last month. The book is the result of seven years of compiling more than 500 investigations of crane accidents that Haag's crane group, based in Sugar Land, Texas, has conducted since 1983.
Until now, few have pointed to a cause for the 2012 accident. Officials with the building's construction manager, Lend Lease, told ENR the crane operator put the unit in weather-vane mode, as standards and best practices dictate; city officials concurred. Further, the engineer that designed the crane's tie-ins characterized the incident as an "act of God."