BOSTON (AP) — Officials say a train motor failed on Boston's subway line and caused the train to derail, affecting hundreds of people during their morning commute.

The Massachusetts Bay Transportation Authority says the motor on the last car of a Red Line train failed Wednesday, causing it to derail around 9:30 a.m. Passengers say the train bounced on the tracks, causing a window to break and spray glass.

The MBTA says the train re-railed itself before stopping at Andrew Station. Officials estimate about 300 feet of tracks was damaged.

No injuries were reported.

Shuttle buses were deployed to transport passengers, and officials say service was interrupted for nearly eight hours.

The MBTA says the cause of the motor failure is under investigation.