Developer: Weight of Addition Is Behind NYC High-Rise Scare

Construction crews have begun stabilizing a Manhattan high-rise at risk of partial collapse, but the process could take days and continue to cause headaches around nearby Grand Central Station. The developer of a massive project to convert offices at the top of the building into residential units tells the Wall Street Journal that two supporting columns on the 21st floor may not have been properly reinforced. Nathan Berman of MetroLoft said the project involves widening roughly 15 upper floors, beginning on the 22nd. "This additional load that we put on those floors caused those two particular columns to collapse," he said. "Why those particular two columns and nothing else? We don't know. We're investigating that."

Berman said the failure appears limited to a small corner of the addition and insisted that "95% of the building" remains structurally sound. Firefighters were called to the scene about 8am Tuesday, leading to a rapid evacuation that cleared much of a city block between the Chrysler Building and the UN. Nine neighboring buildings were also emptied as a precaution. Mayor Zohran Mamdani warned New Yorkers to continue avoiding the area, per the New York Times.

The conversion of the former Pfizer headquarters—nearly 1.6 million square feet across a full block—aims to create about 1,600 apartments, a quarter of them affordable, plus amenities including a rooftop pool. City buildings chief Ahmed Tigani said the project's plans underwent a lengthy review over two years. The mishap lands in the middle of a broader boom in office-to-residential conversions, which have become a key source of new housing in New York and other cities, even as architects warn that the complex engineering involved leaves little room for error.