LOS ANGELES >> Trains were again running by the University of Southern California early Sunday, a day after a light rail train slammed into a car injuring 21 people, including the train operator and the driver, who was in critical condition.

The Metro Expo Line train was heading east toward downtown shortly before 11 a.m. Saturday when authorities said it appeared the car’s 21-year-old driver didn’t see it and tried to make a left turn across the tracks from a major thoroughfare.

The car, a silver Hyundai, was all but demolished, and firefighters had to use the Jaws of Life to extricate the driver. The first two of the train’s four cars slightly derailed, but they remained upright.

The train’s operator Kenneth Goss, a 29-year Metro veteran in his mid-50s, was taken to the hospital in serious condition, but he was released and recuperating at home with family Saturday night, Metro spokesman Jose Ubaldo said.

Nineteen passengers on the train suffered lesser injuries, mainly cuts and bruises. Eight were taken to hospitals, and the others were released.

The cause of the crash was under investigation. But Metro supervisor Diljiat Sandhu said it appeared that the car’s driver was attempting to turn left at a grade crossing and didn’t see the approaching train.

The train was taken to the Long Beach Blue Line yard for inspection and repairs, and video from its cameras would be sent to police as is usual in such an accident, Ubaldo said. He said Metro would wait for the conclusions of the law enforcement investigation before finishing its own.

With the wreckage off the tracks, city workers repaired a damaged traffic light pole and trains were back up and running along the full line by 5 a.m. Sunday.

The crash occurred in an area where Metro trains travel down the middle of Los Angeles’ Exposition Boulevard, with cars traveling east or west on either side. The passenger cars are covered with a bold black-and-yellow warning sign that reads: “Heads Up! Watch For Trains.”

On the north side of the boulevard is the USC campus, and on the south side is an entrance to Los Angeles’ Museum of Natural History. It appeared the driver attempted to cross at a small side street that dead-ends at a campus parking lot, officials said.

“We always say, ‘look at the train, look at the lights, pay attention to your surroundings and follow and respect the traffic lights,'” Ubaldo said.