FLATLANDS - A Brooklyn grandmother was pinned underground Monday after part of the sidewalk collapsed.

Police say Fay Brody was putting her grandchildren into a car when the sidewalk opened up and she fell through. A witness says he tried to pull Brody out, but a piece of concrete was on top of her. Firefighters say it took seven minutes to rescue Brody. Her grandchildren were not injured.

Firefighters say the sidewalk collapse is very unusual. The cause of the collapse is unknown. Several city agencies investigated the scene to make a final determination.