Four inmate firefighters remained hospitalized in critical condition Wednesday after a head-on crash north of Los Angeles that killed a colleague and an elderly driver.

The four were among a dozen firefighters hurt Tuesday when a Subaru Forester sport utility vehicle veered into oncoming traffic on Highway 138 south of Gorman and hit a truck carrying members of the fire crew, authorities said.

Seven other inmates and a Los Angeles County firefighter who is the crew's foreman were treated at hospitals and released, Los Angeles County Fire Department Inspector Matt Levesque said.

The crash killed inmate firefighter Fernando Sanchez, 25, who was ejected from the back of the truck, authorities said.

The Subaru's driver was identified as Milton Edward Bacon, 83, of Gardnerville, Nev.

Bacon was heading to Santa Barbara when the crash occurred, coroner's Capt. John Kades said.

The cause of the crash remained under investigation.

Sanchez was from San Diego County and had been sent to prison for possession and sale of narcotics, California prisons spokesman George Kostyrko said. He would have been eligible for parole in January 2012.

Three of the inmates were pinned underneath the truck when the first rescue engine arrived along the narrow rural highway, fire Capt. Mark Savage said.

A truck towing a forklift happened to be caught in traffic backed up by the crash. A firefighter asked the truck driver to unload the forklift, and he freed the trapped inmates.

"They saved those folks," Savage said. "It would have taken 45 minutes to get heavy equipment to that remote location."

The crew was headed back to their camp near the crash site in San Francisquito Canyon in Saugus after completing a project, Savage said.

They were riding in a crew-carrying vehicle or CCV, which has a cabin front and an enclosed back with air conditioning and bench seating.

Los Angeles County maintains 10 permanent fire camps, including five in conjunction with the California Department of Corrections. Inmate crews battle wildfires and work on brush clearing and construction projects.

"This is a bad day for LAFD. We lost an extended family member who worked hand-in-hand with our firefighting crews," Savage said.