CONCORD (CBS SF) — One person was dead, another seriously injured and suspect at large in a Saturday evening freeway shooting on Highway 4.

The California Highway Patrol said officers responded to reports of the shooting at around 6:35 p.m. on Highway 4 just east of Port Chicago Highway in Concord.

READ MORE: Flames Reach Ancient Sequoias; Crews in Pitched Battle to Save Giant Forest Grove

Arriving officers found two gunshot victims in a bullet-riddled black Toyota Camry. One victim succumbed to their wounds and the victim was taken to the hospital suffering from moderate injuries.

READ MORE: PG&E Says Light Rain After Long Drought Led to Lights-Out Across Bay Area

Investigators said the unknown suspect vehicle fled the scene. No description was provided. As a result of the shooting, the victims vehicle crashed into the metal guard rail at the top of the Port Chicago offramp.

CHP shut down all westbound lanes of Highway 4 Saturday night while they collected evidence.

MORE NEWS: Woman Fatally Shot, Another Wounded Outside Pittsburg 7-Eleven Store

Detectives were requesting assistance from the public in gathering the details surrounding this incident. If you or anyone you know have any information that might be helpful, please call the CHP Investigative Tipline at 707-917-4491.