A three-story apartment building at 1321 Flatbush Ave. in Brooklyn collapsed just after 4 p.m. Wednesday, falling into an open construction site at 2625 Bedford Ave., where workers were actively excavating.

Part of the neighboring building at 1323 Flatbush Ave. was also damaged, with an exterior wall sheared away and apartments left exposed.

FDNY Chief of Department John Esposito said firefighters arrived in less than a minute and found people trapped in the adjacent building, immediately removing them from danger.

Two people were killed and 17 others injured, with four in critical condition and seven children among the victims, FDNY Commissioner Lillian Bonsignore said.

Rescuers still do not know how many people were inside the building when it fell, and officials warned the death toll could rise as the search continues for days.

Witnesses described frantic scenes: The New York Post reports that resident Anderson Velez received a call from his wife buried in rubble with their two young children before the line cut off, and that a pregnant woman was pulled alive from the debris.

Reverend Alfred Joseph, whose church sits across the street, told the Post one woman quietly waited for news of a husband still in the rubble. Mayor Zohran Mamdani called it an incredibly challenging and fast-moving situation, with dangerous voids beneath the surface.

More than 250 FDNY personnel responded, according to the New York Post, and firefighters searched void spaces through the night and into Thursday using hand tools and a suction machine.

ABC7 New York reports that K-9s detected two areas of interest for possible scents, and that the FDNY is deploying a drone while removing debris with buckets and vacuum trucks. Four people were rescued during the 6 p.m. hour alone.

Commissioner Bonsignore warned that collapse operations are extremely dangerous because moving too quickly risks disrupting the debris piles, and Chief Esposito described the site as very unstable, with crews working to prevent a secondary collapse.

The investigation is focused on the adjacent construction project. The city's Department of Buildings said the developers had an active permit for excavation and foundation work, and a full stop-work order has since been issued while investigators determine the cause.

According to Spectrum News NY1, the DOB recorded multiple issues with the project in May, including working during a stop-work order, lacking proper overhead protection for neighboring properties, and failing to conform to approved construction drawings.

NY1 also reports that HPD has filed 98 violations against 1321 Flatbush Ave. dating back to 1972, and ABC7 notes the building had a resolved violation from April.

The NYPD is asking the public to avoid the area around Bedford and Flatbush Avenues, with street closures and traffic delays expected after Mamdani announced Flatbush Avenue is closed from Clarendon Road to Bedford Avenue, per NY1.

New York City Emergency Management opened a reception center with the Red Cross at the Flatbush YMCA; the Red Cross figures for registrants differ across outlets, with ABC7 reporting 11 adults and two children and the Post reporting 12 adults and three children across six households.

Recovery, rescue, and investigative efforts remained ongoing Thursday, and Governor Kathy Hochul said state partners were offering full support as authorities investigate.