A section of a 20-storey residential building partially collapsed in New York City on Wednesday morning, and authorities say there are no injuries.
Firefighters and emergency responders searched into the afternoon for anyone who may have been trapped under the mounds of rubble outside the building, which is part of a public housing development in the Bronx.
The whole building just - you heard a loud boom, and the thing just exploded, and it fell down just like that, said one witness who spoke with CBS News.
The collapse seems to have originated from an explosion in the ventilation shaft of a boiler room, the city's fire commissioner Robert Tucker said in a news conference.
No apartments were damaged, but as a precautionary measure, some residents have been evacuated. The New York City Housing Authority is currently investigating the incident, which had previous violations related to plumbing and facade safety.