Eight people have died and 18 more were injured after a three-storey building collapsed in the Flatbush neighbourhood of Brooklyn.
Witnesses described hearing a loud boom and seeing dust in the air as the building came down and fell into a construction pit where people were working on Wednesday.
The building - which contained apartments and a store - was adjacent to an active construction site.
New York Mayor Zohran Mamdani, described a harrowing scene, saying workers "who had only barely survived themselves turned back and dug victims out of the rubble".
The city's fire commissioner, Lillian Bonsignore, said firefighters were on the scene within minutes and called their actions "incredibly heroic".
Speaking on Thursday, she said fire crews "are still in a recovery phase".
Despite the hard rain and falling temperatures at the site, she said, their efforts would continue until every victim was located.
The building at 1321 Flatbush Avenue in Brooklyn was constructed in the 1930s.
It was adjacent to a construction site where plans have been approved for a new building that will include 64 residential units and a grocery store on the bottom floor.
Active work was happening on the site when the incident occurred. It appears part of the building fell into the construction pit next door, trapping and killing some workers.
It is too early to say what caused the building to collapse at around 16:00 local time (21:00 GMT) on Wednesday, but officials say they are looking into the possibility of filing criminal charges.
The structure was fully occupied by residents, and construction workers were performing excavation work on a neighbouring site at the time, according to CBS News, the BBC's US partner.
It's not clear if the construction had anything to do with the collapse, and the city's buildings department says it is still investigating.
Investigators have said developers have active permits for excavation and foundation work associated with a new building project. The developer has been identified as Robert Fischman.
In a post on X, Brooklyn District Attorney Eric Gonzalez says: "We are working closely with the Department of Buildings and our law enforcement partners to determine whether any criminal conduct contributed to this tragedy."
Mayor Mamdani later emphasised this message in a news conference, saying that every entity involved in the building and the construction site will be investigated, and held accountable.
Eight people - six adults and two children were killed, authorities said. Two were construction workers.
Mamdani said that six people were pronounced dead at the scene, while another two died in hospital.
Four of the injured are firefighters. One person still in hospital is in a critical condition.
None of the victims have yet been identified by officials.
Mamdani said they were "our friends and our neighbours. Our parents and our children.
"Young families building their lives in our city, and immigrants from Mexico, Colombia, Ecuador, Trinidad and beyond."
More than 250 firefighters responded to the scene, working through the night to locate trapped victims.
Reporters at the scene described the chaos, which occured on a normally busy avenue of Brooklyn.
The head of the NY Department of Buildings, Ahmed Tigani, said in a news conference on Thursday that there were no violations of building codes reported at the building before the collapse.
He said the property developer has ties to at least 100 other sites around the city, which are also now being checked.
Forecasters predict scattered showers throughout Thursday, and then heavy rain across the New York region from 17:00 local time (22:00 GMT).
The CBS meteorologist for New York, Tony Sadiku, warns there is a possibility of severe storms later in the evening, which could hamper search and recovery efforts.
One man told the BBC that he had just delivered an Amazon package to apartment number 2 in the complex minutes before it crumbled.
The man, who didn't want to share his name, described hearing a huge, loud "boom" sound.
He was shocked to see the building he was just in reduced to debris, he said. Within a minute or two the fire department was on the scene with several trucks, and they quickly closed the street.
"I live literally right behind the building", Emmanuella Carilus told the New York Times. "It sounded like a big boom and you just heard a bunch of screaming."
The husband of one woman who was filmed being rescued from the rubble spoke of his relief to CBS News New York
"She is alive. She is still alive. I'm very happy. I'm very happy. I'm very happy. I thank all of you guys. She's pregnant, six months," he said.
