Part of a high-rise apartment building in New York City has collapsed, leaving a corner of the building in a pile of rubble.

An incinerator shaft on the corner of a 20-story New York City apartment building collapsed with a loud crash into a pile of rubble Wednesday morning after reports of a gas explosion.

The city’s fire department said it had no immediate reports of injuries. It said it was responding to a report of a gas explosion that collapsed the incinerator shaft of the city-owned public housing building in the Bronx.

“An investigation is underway to determine the cause of this event and the extent of any damage beyond the reported exterior damage to the chimney,” the city’s housing authority said in a statement.

Videos taken by nearby residents showed a cloud of dust billowing over the block moments after the collapse, which happened around 8:10 a.m. News helicopter footage showed a rescue dog bounding over the huge pile of bricks at the bottom of the building, sniffing for anyone who might be buried under the rubble.

A witness, Diamond Freeman, told WPIX-TV that there was a loud boom.

“And all the side of the building just fell. It was crazy. All you see is smoke,” Freeman said.

The mound of rubble was littered with air conditioners, with appeared to have been ripped out of apartment windows by the falling bricks.

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Kaz Daughtry, the deputy mayor for public safety, said on X that some apartments were being evacuated as a precaution and services for them were being made available at a nearby community center.

Mayor Eric Adams said he was briefed about the emergency and officials were still getting a full assessment. “Please avoid the area for your safety,” he wrote on X.

Officers established a perimeter around the area as firefighters, city building officials and the Con Edison utility provider were on the scene. Police said they received 911 calls about a building collapse just after 8 a.m. at the Mitchel Houses building.

Incinerator shafts in New York City buildings were once used to dispose of trash, which was then burned on site. But they have largely been replaced with trash compactors, which can use the same chutes.

Around half a million New Yorkers live in aging buildings run by the largest housing authority in the nation, known as NYCHA. Tenants in the system’s have complained for decades about dangerous or unsanitary conditions including rodents, mold, and heat and hot water outages.

Many of the properties date back to the 1940s, ‘50s and ’60s. In 2019, a federal monitor was appointed to address chronic problems like lead paint, mold and lack of heat. When he wrapped his five-year term in 2024, the monitor, Bart Schwartz, noted that the overarching issue for residents remained the “poor physical state of NYCHA’s buildings.”(AP)