A Pleasant Hill woman died and her passenger was seriously injured early Saturday morning when their vehicle struck a Caltrans vehicle on the San Francisco-Oakland Bay Bridge, the California Highway Patrol reported.

CHP identified the driver as 26-year-old Haylie Ann Eisele, who was operating a Kia sedan at around 4 a.m. on eastbound Interstate 80 near the Treasure Island off-ramp at the time of the crash.

Investigators said the Kia was traveling in the far-left lane when it abruptly swerved onto the left shoulder, striking a parked, unoccupied Caltrans vehicle operated by the California Department of Transportation.

Eisele was pronounced dead at the scene. Her passenger, who has not been identified, sustained serious injuries in the crash. A dog that was also in the vehicle was injured as well.

Authorities have not released any further updates on the passenger's condition.