PHILADELPHIA — Investigators say the operator of a one-car commuter train that crashed into a parked train at a suburban Philadelphia terminal last month told them he tried to stop the vehicle but was unable to do so.

The National Transportation Safety Board says in a preliminary report released Tuesday that the operator had reported slippery rail conditions that caused his Southeastern Pennsylvania Transportation Authority train to miss an earlier station.

The Norristown High Speed train crashed into the unoccupied train car at the 69th Street Terminal in Upper Darby on Aug. 22. The crash sent the operator and 42 passengers to hospitals.

The operator slid past the platform at the Gulph Mills station, near the other end of the line, and reported slippery rails. But SEPTA officials said it received no other such reports.