ORINDA (CBS SF) — A wrong-way driver on Highway 24 near the Caldecott Tunnel early Sunday triggered a horrific head-on crash that left two people dead and five others injured.

The California Highway Patrol said the collision was reported at 1:52 a.m. on westbound Highway 24 between Fish Ranch Road and Wilder Road in unincorporated Contra Costa County. All lanes of Highway 24 were closed for about two hours as emergency crews responded to the scene.

The California Highway Patrol reported that a silver Saturn Vue and a black Toyota Camry collided head-on and the one male passenger from the Saturn was pronounced deceased on scene.

Meanwhile, the Saturn’s driver, 35 years old, was transported to John Muir Hospital where he died of his injuries. All five males, who were in the Toyota Camry and in their 20s from Daly City, were transported to local area hospitals with major injuries.

CHP Officer Brandon Correia said the damage to both vehicles was “catastrophic.”

Correia did not detail what evidence investigators found on scene, but said signs indicate that he was under the influence.

“There are many things we look for, whether we smell it, see evidence, beer cans. All of these types of things are prevalent in this case. Doesn’t mean that 100% a person is impaired, but it leads us to a conclusion that maybe this person is impaired. We’ll find out that definite answer once the autopsy comes back,” said Correia.

The victim driver of the Toyota is not suspected of alcohol or drugs.

A call for mutual aid went out to local fire department emergency crews to help with the injured.

Investigators will be checking surveillance cameras at the Caldecott Tunnel for the possibility that the suspect driver entered Highway 24 on Fish Ranch Road or Wilder Road.

Correia said every available officer will be on duty during the July 4th holiday, a staffing level known as “maximum enforcement.”

“Driving impaired is 100 percent preventable 100 percent of time. Don’t let anybody tell you anything different. Whether it’s alcohol, marijuana, anything that impairs you when driving a motor vehicle is preventable. There’s rideshare, you can take public transit, something. Make a better choice to not drive impaired. It’s OK to have some beers to have some whatever you’re having. But don’t drive and then endanger your life, your passenger and an innocent party driving on the opposite side of the road,” said Correia.

If anyone witnessed this collision or the events leading up to it, please contact Contra Costa CHP in Martinez, (925) 646-4980.

KPIX 5’s Kiet Do contributed to this report.