The rear wall of a three-story South Slope building completely collapsed on Friday, authorities said.
The back wall of the brick building on 16th Street between Seventh Avenue and Jackson Place came crashing down at 2:10 pm, a fire department spokeswoman said.
The building is currently under construction and no one was injured at the time of the collapse, according to officials.
The fire department is conducting a structural stability inspection on the building, which the Department of Buildings issued a complaint against in August for illegal after-hours construction work.

Wall fall down: The collapsed rear wall of a Park Slope building seen through the front door.
Photo by Elizabeth Graham