The two vehicles at Manheim Auction, 20401 Cox Avenue, were being moved when an employee lost control of one of them. One of the cars veered into bystanders.
"A car starting accelerating back of lanes up to 40 miles an hour knocked about three or four people to the ground," Moe Baraket, witness, said. Baraket said it appeared the driver, an elderly man who walked with a cane, accelerated by accident. "One guy flew up in the air."
Four people, including the driver, were taken to hospitals. None of the injuries was life threatening, officials said.
The accident remains under investigation, but the driver was cited with going to fast for conditions.
Manheim's general manager calls the crash a rare event at the auction house, which has hundreds of cars.
"Manheim takes a lot of pride in making sure we have a very safe environment," Mike Cesta, Manheim Auto Auction, said.