(AP) - A one-car commuter train crashed into a parked train at a suburban Philadelphia terminal early Tuesday, buckling the floors of both cars and injuring more than 30 passengers, authorities said.

None of the injuries was considered life-threatening, said Heather Redfern, a spokeswoman for the Southeastern Pennsylvania Transportation Authority.

"Some were considered walking wounded," she said.

The train operator, who was treated at a hospital and released midday, submitted samples for drug and alcohol tests, said Ruben Payan, lead investigator for the National Transportation Safety Board. He said the NTSB also had asked to interview the operator Wednesday, along with the operator of a train on adjacent tracks and transit supervisors.

The Norristown High Speed train crashed into the unoccupied train car at the 69th Street Terminal in Upper Darby around 12:15 a.m., tossing passengers from their seats.

"I heard the train going real fast ... like, super-fast," passenger Raymond Woodard told WPVI-TV Woodard. "And I looked up, and I saw that we're at 69th Street and said, 'Why are we going so fast?' And then we just hit the train. Boom! I fell out of my chair, glass from the window shattered, I hit my head. Everybody was on the floor."

Neither train car derailed, and Payan said damage overall did not appear to be major. But he said investigators wouldn't know for sure until the two cars could be inspected in a shop.

He said it could take up to a year to produce a final report on the cause and safety recommendations.

"We haven't ruled anything out right now," Payan said, adding that video recovered from both cars will be reviewed.

The transit agency had put the number of injured at 42. But the NTSB said the total number of injured was 33 - 32 passengers and the train operator.

In February, four people were injured in a crash near the 69th Street Terminal involving three out-of-service commuter trains. At the time, SEPTA said one train rear-ended another on a loop where trains turn around to get back into service. Cars from that accident derailed and hit a third train on nearby tracks.