A window washer fell 11 stories from a San Francisco building before bouncing off a moving car, police said.
The man, whose name has not been released, suffered life-threatening injuries and was taken to a hospital, San Francisco police Officer Albie Esparza said.
The accident happened about 10 a.m. in the city's Financial District. Fire officials initially reported that the man was a construction worker. The back of the car he landed on was smashed in, but Esparza said the driver was not injured in the incident.
The driver, Mohammad Alcozai, told KGO-TV that he was happy to be alive and praying that the worker survived.
He said the impact came shortly after he made a left turn, adding that his car's roof almost completely collapsed in the accident.
Maa-Becca Tucker was walking past the crash when she saw the worker lying on the ground. She said he wasn't moving.
Tucker described the scene as "crazy" and said a woman standing next to her was praying for the man as firefighters took him away in an ambulance.
Some witnesses said the man had been clinging to a rope, which could be seen dangling from the roof of the building.
The man worked for Century Window Cleaning, based in Concord, Calif., said Peter Melton, a spokesman for the state division of occupational safety and health.
The company was cited for one serious violation and three other violations in 2008, one of them related to instructing window-cleaning employees in the proper use of all equipment provided to them and supervising the use of the equipment and safety devices to ensure safe working practices, according to federal records. The company was fined more than $6,500, though the fine was eventually reduced to a little more than $2,700.
The company had no immediate comment on Friday's incident.