A three-story building collapsed into an adjoining construction site in New York City's Brooklyn on Wednesday afternoon, killing at least two people and injuring at least 17 others as firefighters searched the rubble for anyone still trapped.

What do we know about the New York building collapse?

The collapse happened at about 4 p.m. local time (2100 GMT) in the Flatbush neighborhood. Fire Department Chief John Esposito said the four-unit apartment building, dating from 1930, fell into a pit where excavation work was underway. The cause is under investigation. 

Fire Commissioner Lillian Bonsignore said 19 victims were known, seven of them children, but did not say whether those killed were children or adults. Four of the injured were in critical condition.

More than 250 firefighters and paramedics were deployed, using drones, search dogs and power saws. 

"We do not know how many people are still in the collapse zone, and this will be a prolonged operation," Bonsignore told reporters. 

Esposito said it would take several days to search the whole site: "We do not know how many people are missing overall." 

At least four survivors, including a pregnant woman, were pulled out two to two and a half hours after the collapse, local media reported.

What did NYC Mayor Mamdani say?

New York City Mayor Zohran Mamdani hailed the first responders, saying, "This has been an incredibly challenging and fast-moving situation, with precarious wreckage to navigate and dangerous voids beneath the surface. This type of rescue is exactly what the FDNY trains for."

He also said his "heart is with the families and loved ones mourning those we have lost" and wished a speedy recovery to the injured, in a post on X.

Meanwhile, Buildings Commissioner Ahmed Tigani said developers had approved plans for a three-story building on the neighboring lot and were seeking permission for a nine-story one. 

Resident Anderson Velez told the New York Post his wife and their two children, ages 7 and 2, were trapped. 

"She called me when the building collapsed while she was inside with rubble on top of her. She was screaming for someone to help get my son out and then the call cut off," he said.

He later found out they had been pulled out alive.