Two workers were seriously injured Friday in a collapse of a two-story residential structure that was under demolition in Crown Heights, fire officials said. 

FDNY Deputy Borough Commander Joseph Ferrante said the workers were pinned when the roof of the Lincoln Road building fell on top of them just before 2 p.m.

Rescuers took more than an hour to free them, Ferrante said.

Both workers are being treated at Kings County Hospital.

The Department of Buildings said “active construction permits” are in place to turn the structure into a five-story building.

Check back for updates on this developing story.