How a Brooklyn Building Collapse on Flatbush Avenue Unfolded, Minute by Minute

The first sign was a sound. Outside a three-story building at 1321 Flatbush Avenue in Brooklyn, loud popping cut through the ordinary noise of the street. Benewaa Bonsu, who was walking past the construction site next door, said her first thought was gunshots.

James Williams, who works at a deli across the street, had grown used to the racket from that site, where crews were digging below ground to prepare a foundation for a new building. This time he looked out and saw bricks dropping from the building into the pit. He described the sound as a rapid click, click, click, and remembered thinking, "Oh, hell, what is going on?" Then, he said, the building began to crumble.

Inside a third-floor apartment, a video captured the moment. A young boy takes milk from a refrigerator while a toddler plays on the floor. One wall of the room suddenly falls away into open air, with pieces of it collapsing back inward. The boy with the milk runs, and the toddler scrambles backward as a woman screams from the next room. Within seconds, the whole building would be gone.

From the deli, Williams watched the front of 1321 Flatbush slide away, and then the side. A check-cashing office on the first floor, one he often visited, seemed to vanish. He saw clothes and a microwave fly out of the open structure into the dust, and he heard people screaming. The rest of the building then came down, taking with it an entire wall of the building next door and exposing bedrooms, closets and hallways. Meir Ballas, 36, watching through the window of the Metro T-Mobile shop where he works, described white debris rising like smoke and continuing to come. He saw construction workers outside the perimeter holding their heads in their hands. Three construction workers would later be named among the dead. Nearby, Kendall Cresci jolted upright, telling her fiancé, Pat Cunningham, that it felt like an earthquake. He had headphones on and felt nothing.

Video from a neighboring apartment shortly afterward showed construction workers scrambling over the debris as sirens approached. The mother and the two boys from the third-floor video were rescued quickly. By Thursday they were recovering from injuries, according to the boys' father, who had not been home.

Firefighters and paramedics flooded the scene, hauling brick and concrete aside in the excavation pit to search for survivors. Ambulances waited for patients. Drones soon hovered overhead, some flown by emergency workers and others by news crews. A fire truck extended its ladder into the exposed apartments next door, which looked like the cross-section of a dollhouse. One man tried to cross the police tape and was stopped by an officer. His wife was inside, he said, and she was six months pregnant. He waited across Flatbush until a reporter brought word that she had been rescued; more than a dozen firefighters had carried her out on a stretcher. He wept, and later told an impromptu news conference that she was alive.

As darkness fell, families gathered on Flatbush awaiting word on missing relatives. Crews worked through the night, finding survivors where they could and, increasingly, those who had not lived. The family of Edgar Santiago Sapón Gutierrez, a 26-year-old construction worker, searched sidewalks near the site and then the city's agencies for the dead. "We went to the morgue and didn't find him," said Marisela Vasquez, 35, whose niece is married to him. Returning to the site early in the morning, they saw emergency workers pulling bodies from the rubble.

The recoveries were logged by the clock: a man in his 30s found and pronounced dead at 4:50 a.m. Thursday, another man at 5:44, another at 6:05, and one more 28 minutes later. Firefighters carried them on stretchers, covered. Gutierrez's family was then told he had died. He leaves a 6-year-old son.

The careful work continued into Thursday afternoon as rain arrived, with rescuers moving slowly so as not to disturb debris and hurt anyone who might be beneath it. Shortly after 4 p.m., 24 hours after the collapse, the Fire Department declared the search over. Attention now turns to the excavation next door, the oversight of the site, and the families left behind.