Firefighters rescued a driver whose vehicle was trapped in a drainage culvert after careening off the Capital Beltway early Saturday morning.

A car left the road traveling on the Inner Loop of the Beltway at about 4 a.m., near Kenilworth Avenue in Greenbelt. The car veered down a steep embankment before plummeting 25 feet into the drainage ditch, according to Mark Brady, spokesman for the Prince George's County fire department.

It's not clear what caused the car to leave the road, authorities said.

The driver of the vehicle was rescued by Berwyn Heights firefighters, who had to help the patient escape from a vehicle as it was pinned against a concrete wall in the drainage culvert.

The driver was transported to a local hospital with non-life threatening injuries.