SAN FRANCISCO -- San Francisco police officers are responding to the Richmond District Monday night where a mail carrier apparently fell out of his truck and the driverless vehicle crashed into a parked car.

Police Lt. Lyn Tomioka said officers were called to the area of 21st Avenue and Clement Street at about 4:45 p.m. in response to reports of an unconscious mail carrier. He was taken to a local hospital.

Albert Levy, owner of Aladdin Rugs on the corner of Clement and 21st, said the mail carrier fell out of the truck, apparently suffering from a medical problem.

When he fell, Levy said, the truck kept going without a driver, traveling about half a block on the wrong side of the street and crashing into a minivan.

Levy said he did not know the man.

"He was not our regular mailman," Levy said.