FREEDOM  (AP) — A head-on crash has left four people dead and four others seriously injured when a car packed with teens collided with a pickup truck in rural Santa Cruz County

The black Mercedes sedan — a so-called “party” on wheels — crossed into oncoming traffic about 8 p.m. Sunday in Santa Cruz County, hitting a gray Ford F-150 truck head-on, California Highway Patrol Officer Brad Sadek tells the San Francisco Chronicle.

The driver of the Mercedes and two of its six passengers died at the scene. Another Mercedes passenger was taken to a hospital, where she was pronounced dead. None of them wore seat belts, and their names haven’t been released.

The driver was identified as a 22-year-old Watsonville man. The passengers who died were a 19-year-old woman, an 18-year old man and a 16-year-old girl.

The 56-year-old man driving the truck and three other Mercedes passengers went to hospitals with major injuries.

The crash is under investigation, but Sadek says alcohol or drugs may have been a factor.

Evidence of drinking was found at the crash site, Sadek said, and witnesses reported seeing the Mercedes swerving, crossing the double-yellow line and traveling at high speeds before the crash.

“It sounded a bit like there was a party going on in the car,” Sadek told the newspaper. “The more people you pile into a car, it greatly increases your chances of being in a collision. This is an unfortunate situation of no seat belts and alcohol.”

The wreck closed the road and left one vehicle overturned and another smoking. Firefighters tore apart the Mercedes to release the trapped victims.