4 Times Square Hoist Collapse: The Handling of a Potential Disaster

A 48-story temporary, aluminum-pipe, hoist-support structure supporting the personnel lift of the Conde Nast Tower under construction at Times Square, suddenly started to collapse in the early morning of July 21,1998. A two-story segment of the pipe structure between the 20^th to 22^nd floor buckled and crashed onto itself. The 30 stories above the crashed portion was hanging precariously from the building, leaning outwards onto the Times Square below. With hundreds of people and vehicles in the immediate area below during the morning rush hour, the situation was dangerous and life threatening. The Office of Emergency Management of the City of New York was summoned to the scene to assist in the handling of this major emergency. The NYC Commissioner of Buildings assembled a team of technical experts form the Public and Private sectors to evaluate and stabilize of the partially collapsed structure. LZA Technology was retained to lead the technical efforts of the evaluation, stabilization and eventual demolition. This paper chronicles the author's experiences during this emergency. It also outlines the approaches and methods used to evaluate, stabilize and eventually demolish the partially collapsed structure.