Three people were killed, and one is “fighting for their life” following an overnight fire at a Queens home that did not have a smoke detector, the FDNY said.

FDNY Commissioner Robert S. Tucker and Chief John Esposito described the home very crowded with block stairways and exits, occupants living in the basement, makeshift walls and an abundance of extension cords.

"It makes it much more difficult for our firefighters," said Esposito. “There was a wall through the middle of the kitchen.”

Fire officials did not detail the cause of the fire, saying it was under investigation. Details about the victims have not yet been released.

Three firefighters suffered minor injuries.

Tucker said the tragedy is hard on responding firefighters.

“…Not because it's Passover and Holy Week – it’s because when we come out, we want to save lives. That's what we are here for,” he said. "Smoke detectors save lives. We are not encouraging – we are begging all New Yorkers to have a working smoke alarm.”