Anthony Imbronone III was arrested on suspicion of DUI and vehicular manslaughter in a crash reported around 10:30 p.m. by a resident who heard a large crash on Leavesley Road east of New Avenue, CHP officials said.
A preliminary investigation by the CHP indicates that the vehicle, a 1997 Ford Mustang, was heading east on Leavesley Road when for some reason it turned left while negotiating a right curve on the roadway. CHP officials had initially said the car was a 1998 Mustang.
The vehicle passed solid double yellow lines, slid off of the roadway and crashed into a concrete drainage ditch abutment.
Four passengers, three 18-year-old women and a 24-year-old man, in the vehicle were pronounced dead at the scene.
Imbronone, the sole survivor, was transported by ambulance with major injuries to Saint Louise Regional Hospital, where he was then transferred to a helicopter and airlifted to San Jose Regional Medical Center.
He was arrested on suspicion of DUI and vehicular manslaughter, according to the CHP. Officials say drugs and alcohol were found inside the car.
As of Wednesday morning, Imbronone was still being treated at the hospital.
The CHP is continuing to investigate the fatal crash. Anyone who may have information about the case is asked to call the CHP's Gilroy/Hollister office at (408) 848-2324.