A piece of metal broke off an interior up escalator at the 24th St. BART Station at 7:30 p.m. and hit one woman in the knee, causing an injury that required a medical escort. Three others were lightly injured by the subsequent pile-up.

“It hurts like hell,” said Meredith MacFayden, who was below the woman who was hit. She said that when the woman was hit, other passengers behind her stopped and were pushed by passengers below them, creating a pile-up “like a domino effect” until someone pushed the emergency stop. MacFayden’s leg was bruised by pressure from passengers below her pushing up.

“She got the brunt of it,” said MacFayden of the first woman. “She got it worse because everyone was going on her leg.”

“People were coming up the escalator like this,” said passenger Carlos Andrade, who suffered back pain from the pile-up, making an upward motion. “The piece of metal hit her, and she fell down.”

The woman, whom Andrade described as 60 years old or so, seems to have been hit by the broken metal bar at knee level, though it’s unclear whether it snapped off into her leg or the escalator pushed her into the broken shard. Either way, Bogdan Marcol, another passenger who was bruised by the pile-up, said he thought it was no minor injury.

“She got hit right at the knee, her knee gave out,” he said, before speculating it might have been as serious as an ACL tear.

The woman was taken away by paramedics at the scene, and the other three people on the escalator were treated for bruises or minor cuts. Two ambulances and one fire truck came to the BART station, and a paramedic captain from the fire department said there were four “minor” injuries total. No one from BART knew how or why the metal piece from the interior escalator broke off when it did, and the escalator is currently closed down.