Why Are Steel Beams Inside a Manhattan Skyscraper Buckling?

On Tuesday morning, firefighters in New York City were called to a skyscraper in Midtown Manhattan after the building showed signs it might collapse. The New York Fire Department (FDNY) arrived at 235 East 42nd Street, near the famous Grand Central Terminal, just before 8 A.M. When they got there, they found at least two steel columns bending and buckling on the 21st and 22nd floors. The floors above them were sagging all the way up to the 26th floor.

The building is a 37-story skyscraper that used to be the New York headquarters of Pfizer, a large drug company. Right now, it is being turned from office space into about 1,600 luxury apartments in a project worth $75 million. Two real estate companies, David Werner Real Estate Investments and MetroLoft Management, are running the project together. The architecture firm Gensler is also involved in leading the design work.

Experts think the buckling may have been caused by too much weight placed on the steel columns during the renovation. Gregory Deierlein, a professor of structural engineering at Stanford University, explained that buildings are designed to hold a certain amount of weight. That includes the weight of the building itself and extra weight, called 'live load,' from people and objects inside. During construction, heavy materials can pile up in one spot and push a column past its limit.

Deierlein said it is also possible that a column was not quite strong enough to begin with, and adding extra weight made things worse. He used a helpful comparison: imagine standing on a floor and noticing that one section has dropped a little — that sag happens when the column below it starts to bend. The column bends because it is carrying more weight than it was built to handle.

Doug Holmes, an engineering professor at Boston University, said the most likely place for something to break is at the joints — the spots where parts of a structure connect to each other. He said these joints handle a lot of force and can fail if they are worn down, rusty, or damaged over time. Any weak spot along the path that carries weight could become a source of failure, he explained.

After people were evacuated from the building and the surrounding area, city engineers and FDNY drones were sent in to inspect the damage up close. Emergency beams and other supports are being put in place to take pressure off the damaged columns while the cause is still being studied. MetroLoft said in a statement that the affected area is only a small part of one of the two buildings on the site. The company said it was thankful that no one was hurt and that no debris fell from the building.

Fixing the damaged columns for good will not be easy, experts say. Deierlein explained that workers would likely need to jack up the floors, put in temporary columns nearby, and then remove and replace the damaged ones. Whether that full repair is possible in this building depends on what the engineering team decides after a closer look. For now, the temporary supports are the most important step to keep the building and the neighborhood safe.