3 articles · Updated · The New York Times · Jul 16
Summary
Two columns that failed in a Midtown Manhattan tower on July 7 were likely missing steel plates required to carry 15 added residential floors, according to structural drawings reviewed by engineers.
Photographs and videos show the columns still had an I-shaped profile, not the boxlike form the plates would have created, leading engineers to conclude most or all of the reinforcement was never installed.
The drawings obtained from the New York City Department of Buildings clearly specified the type and location of the added steel, and engineers said the plates were critical to handling the extra load.
The finding sharpens focus on whether the tower's vertical expansion was built as designed, with the missing reinforcement now emerging as a likely cause of the buckling.