A Queens man was killed at a construction site in Borough Park on Friday afternoon when the building's third-floor ceiling collapsed on him, the NYPD said.

Alex Santizo, 21, was inside 1229 45th St. when the ceiling collapsed around 2:15 p.m., police said. The debris hit him in the head, and he fell through a shaft into the basement, cops said.

Santizo was taken to Maimonides Medical Center where he was pronounced dead, police said.

Police said the building was under construction but could not confirm that Santizo was a construction worker.