VISTA -- A Marine in his 30s was seriously injured when his Jeep went off Highway 78 and smashed into a building Monday, authorities said.

The wreck was reported at 1950 Hacienda Drive, where the Jeep sport utility vehicle reportedly crashed off the freeway into a shuttered Tweeter electronics store about 11:30 a.m., sheriff's Lt. Julie Sutton said.

Oceanside Fire Battalion Chief Rob Dunham said the driver, who was alone in the SUV, suffered head injuries and was taken to Palomar Medical Center in Escondido.

The California Highway Patrol is investigating the crash, because it started on the freeway.