AN INCINERATOR SHAFT on the corner of a 20-storey New York City apartment building collapsed with a loud crash into a pile of rubble 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 an incinerator shaft in the 20-storey building in the Bronx.

Authorities said no residential units were affected.

“An investigation is under way 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.

Video from the scene shows a high-rise with one corner collapsed from the ground floor to the roof.

Videos by nearby residents showed a cloud of dust billowing over the block moments after the collapse, which happened around 8.10am on Wednesday.

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,” they said.

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

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.

City police said they received 911 calls about a building collapse just after 8 a.m. Wednesday at the Mitchel Houses building.

“Upon arrival, officers observed a partial building collapse,” the New York Police Department (NYPD) said in a statement.

Firefighters, city building officials and the Con Edison utility provider were on the scene, as officers established a perimeter around the area.

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 rodents, mould 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, mould 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”.