Sheena Coleman turned 35 on Wednesday afternoon, and was looking forward to a night out. At around 4 p.m. she was at home in her second-floor apartment in Flatbush, Brooklyn, with her 6-year-old son, Hakeem, picking up things from the floor. Her 13-year-old daughter, Zariah, was out at the park, enjoying a school holiday. Their fussy cat, Issac, was somewhere in the next room.

Then Ms. Coleman felt everything shake.

She heard a roar from the direction of the children’s bedroom. Dust was somehow entering the apartment.

She darted into the room. There was a gaping space — “a big, big hole”— right above her daughter’s bed.

The children liked to lean against that wall to watch TV. Now it was letting in daylight.

That didn’t make sense. There was a building next door.

In her memory of those frantic moments, Ms. Coleman picked up Hakeem and swung him onto her hip. She then put him back down, and stepped out the door of her unit to where the hallway should have been.

That’s when the truth of what happened revealed itself.

“I could see the street,” Ms. Coleman recalled on Friday in an interview. “I could hear people screaming, ‘Get out! Get out!’”