BRENTWOOD -- Authorities on Friday continued to investigate the cause of a multi-vehicle crash that injured five people Thursday morning.
The wreck took place just before 7 a.m. on Vasco Road south of Walnut Boulevard in unincorporated Brentwood, said East Contra Costa Fire Protection District Chief Hugh Henderson.
Alcohol is not believed to be a factor in the crash, according to a report from California Highway Patrol, the agency handling the incident.
A preliminary investigation revealed a 2012 Chevrolet Malibu driven by 50-year-old Jaqueline Simpson of Antioch, was travelling south on Vasco Road when her vehicle crossed the center line and struck a 2005 Ford 650 truck driven by Guillermo Bustos, 42, of Concord. Neither driver was injured, the report states.
Simpson's Chevrolet then struck a 1998 Mercedes station wagon driven by Delfina Calderon, 54, of Livermore.
The Ford then collided with a nearby 2009 Ford Focus driven by Donnell Miller, 51, of Antioch, the report continues. Miller's vehicle came to rest on the west shoulder of the road, but Bustos' vehicle continued to roll and collided head on with a 2007 Hummer driven by Douglas Vanhorn, 46, of Brentwood.
The impact caused Bustos' 2005 Ford 650 to spin and then roll down a west shoulder embankment of Vasco Road, the report states.
During the roll, a male passenger in the Ford 650 was ejected. Jose Dominguez, 29, of San Jose, broke his nose, cut his ear and sustained a severe concussion, the report shows. He was taken by medical helicopter to John Muir Medical Center to be treated for major injuries.
Another passenger in the truck was taken by ambulance to Sutter Delta Medical Center. That person's injuries were unknown Friday, officers said.
Miller and Calderon were taken by ambulance to Kaiser Permanente Medical Center in Antioch to be treated for minor injuries.
The CHP on Friday continued to investigated what caused the crash, said Officer James Evans.
Contact Natalie Neysa Alund at 510-293-2469. Follow her at Twitter.com/nataliealund.