A woman driving the wrong way on westbound state Highway 4 in Bay Point Tuesday morning caused a five-car pileup that sent four people to the hospital, a California Highway Patrol officer said.

The collision was reported at 6:05 a.m. just east of the Willow Pass Road exit, CHP Officer John Fransen said.

Fransen said a 30-year-old Pittsburg woman drove her Chevy Camaro east on westbound Highway 4 and struck a Nissan Frontier pickup truck head-on.

The Camaro then collided with a GMC-style pickup truck.

In an attempt to avoid those cars, the driver of an oncoming Ford Explorer swerved but ended up hitting the Nissan Frontier's ride side, according to the CHP.

Meanwhile, the out-of-control Camaro hit a Toyota Corolla.

The Camaro's driver suffered major injuries and was taken to a hospital.

Two other drivers involved in the pileup were taken to hospitals with complaints of pain, while another was taken for medical evaluation as a precaution, Fransen said.

Investigators have not yet determined whether alcohol or drugs were factors in the collision.

The crashes blocked the roadway's two right lanes for more than an hour and snarled traffic in the area for miles.

Anyone who may have witnessed the crash is asked to call the Contra Costa County CHP office at (925) 646-4980.