‘Failures happen during construction’: Office-to-residential conversions are all over NYC, but failures usually get fixed before they get worse

An engineer says the failed columns at the former Pfizer HQ have nothing to do with steel material quality.

The building at the center of this week’s Midtown scare is the former Pfizer world headquarters at 235 East 42nd Street: a 33-story tower built in 1960 that, alongside its neighbor at 219 East 42nd, is being converted by Metro Loft and David Werner Real Estate Investments into roughly 1,600 apartments, the largest office-to-residential conversion in U.S. history.

On Tuesday morning, the FDNY received reports of bricks falling from the building; inspectors found two support columns buckling on the 21st floor and floors sagging up through the 26th. Nine surrounding buildings were evacuated, a “frozen zone” was established from First to Third Avenues, and by Tuesday night, crews had begun installing emergency shoring. No injuries were reported. Metro Loft’s Nathan Berman attributed the buckling to added weight from new floors; while the site had racked up seven DOB violations and roughly $15,000 in fines over the past year for falling debris.

Forensic and structural engineer Joseph Di Pompeo, who has more than 25 years of experience in structural engineering and forensic investigation and has testified as an expert witness before planning and zoning boards, and in New Jersey and New York state and federal courts, said the type of failure visible in photos and video doesn’t support a steel-quality explanation—which is what the FDNY first said at a press conference yesterday.

“There is no material strength number in the formula” for column buckling, he said. “It could be good, it could be bad, it could be terrible, but it still wouldn’t affect what happened here.” Buckling, he said, is governed entirely by two things: how long a column runs between braces, and how much load it’s carrying.

That distinction, Di Pompeo said, points instead toward a loading error: Either the engineering didn’t properly account for the weight being added during the conversion, or construction sequencing put more load on a column than it was ever meant to carry.

“It’s got to be one of those two things,” he said.

Metro Loft’s own account lines up with that framing. Founder Nathan Berman told The Wall Street Journal additional weight added during construction on top of the building likely caused the two columns to buckle, calling the incident “nothing more than a typical construction mishap” and, later, a “freak accident.” He told reporters the project overall was “well engineered, well thought through, and well executed, with the exception of those two columns that could not tak[e the load],” and said the affected area was limited to a small section of one building.

Other conversion work happening in New York City

There’s also a lot of conversion work happening across the city all at once. In 2023, nearly 80 office buildings in New York had already been converted to residences over the prior two decades, with roughly 200 more potentially in play. That pipeline has grown substantially since: Developers are now on track to start 9.5 million square feet of new office-to-residential conversions in 2026 alone, more than double last year’s pace and nearly twice the city’s previous peak in 2008, with New York leading every U.S. metro at more than 16,000 units currently in conversion.

Goldman Sachs estimated in 2024 office prices would need to fall nearly 50% for conversions to be financially viable at scale, and one commercial real estate veteran told Fortune 30% of office buildings are “basically worth nothing” and will simply need to be torn down rather than converted.

With that volume, Di Pompeo said, minor structural issues during construction are common, but they just don’t typically make news.

“A lot of failures happen during construction,” he said. “There’s a lot of failures that happen during construction that nobody hears about, because it’s not a collapse. It gets fixed, and everybody moves on.”

He was skeptical the building’s prior violations tell the real story, either.

“Every building in New York has one,” he said, noting that most citations—like the loose debris incidents on this site—have little bearing on the type of column failure reported this week.

This story was originally featured on Fortune.com