The building at 1321 Flatbush Avenue, near Bedford Avenue, came down just after 4 p.m. It held commercial space on the ground floor and apartments above, and was reported to be fully occupied. It stood at the edge of a construction site, where a one-story structure had been demolished and an excavation pit dug. Construction workers were in the pit when the building fell, and much of the debris landed there, filling it with bricks and wood. A neighboring building that shared a wall with it stayed up, but the wall was torn away, exposing a bedroom and closets.

Early reports from the police department said one person was dead and another critically injured. The count rose through the night and into Thursday. Two people were pulled from the rubble within the first hour, and aerial footage at about 4:45 p.m. showed an injured man being carried out on a stretcher. Roughly 250 firefighters, along with police officers and search dogs, worked through the night using power saws and hand tools, and flashlights after dark. Fire Commissioner Lillian Bonsignore called the work "dangerous and perilous."

Among those trapped was the family of Anderson Velez. His wife called him from inside the rubble with their two children, ages 7 and 2, before the line cut out. Velez later confirmed that all three had been rescued alive.

The cause has not been determined. Buildings Commissioner Ahmed Tigani said workers were excavating the empty lot next to the building when it fell. A complaint filed with the Department of Buildings alleges the subcontractor may have dug out too much ground along the neighboring foundation at once, without following the approved support-of-excavation drawings or the required 45-degree slope. The complaint says the collapse "may have been preventable." City records from a pre-construction inspection in March describe the building's north wall as in "poor" condition, with visible cracks on three of its facades. Officials have not confirmed that the excavation caused the collapse.

The site's owner is a limited liability company run by Robert Fischman. It sought to build a 56,000-square-foot, nine-story mixed-use building, though the city had approved only three stories. Developers hold active permits for excavation and foundation work, and it is unclear how much had been done when the ground gave way. The Department of Buildings issued a stop-work order on March 20 over inadequate overhead protections. Work resumed on April 23, in violation of that order.

Mayor Zohran Mamdani said the Department of Buildings and law enforcement have opened an investigation, and a full stop-work order is now in place at the site. The department is also sweeping about 100 other city sites tied to the five entities involved in the project.