It all unfolded on Fourth Avenue and Carroll Street in Park Slope at about 3 p.m. Sunday.
“We heard a huge crash up in the building, so we all ran down and thought it had landed on our truck — it was a huge metal sound,” said Rachel Crittenden, an eyewitness, as the Brooklyn Eagle reported.
“We all ran that way, and then we saw the stuff hanging from the building and we went to the front. One girl got hit, and the other two got hit by ricocheted pieces.”
Fire officials said the debris crashed down onto the courtyard and atrium of a two-story bar Mission Dolores, injuring three patrons.
Officials said one person suffered serious injuries and two others were treated for non-life threatening injuries.
The Associated Press contributed to this report.