SAN DIEGO — A motorist suffered serious injuries Tuesday morning and was freed from his wrecked pickup truck after he crashed into the back of an armored Marine Corps vehicle on Interstate 15 in the Miramar Ranch North area.

The crash happened around 12:50 a.m. on northbound Interstate 15 near Scripps Poway Parkway, California Highway Patrol Officer Jim Bettencourt said.

A convoy of military trucks was traveling on the freeway when, for unknown reasons, a man driving a 2014 Toyota Tundra pickup struck the back of one of the vehicles, Bettencourt said.

The collision left the driver trapped inside the vehicle and it took crews around 35 minutes to free the motorist from the wreckage, a San Diego Fire-Rescue dispatch supervisor said.

The man was taken to Scripps Memorial Hospital in La Jolla for treatment of serious injuries, the dispatch supervisor said.

No other injuries were immediately reported.