Christina O'Haver, The Union Democrat

The California Highway Patrol on Friday released the names of the two people killed in a fiery head-on crash west of Sonora.

Edward Stanton, 83, and his passenger, wife Jacqueline Stanton, 82, both of El Dorado, perished in the Thursday afternoon accident on Highway 49, CHP said.

The accident happened about 3:30 p.m., near Portagee Lane, when a Toyota pickup truck driven south by Laura Zahm, 57, of Jamestown, suddenly crossed into the highway's northbound lane and struck a Buick driven by Edward Stanton. The Buick burst into flames.

The Stantons died at the scene.

Zahm suffered numerous broken bones and remained hospitalized in critical condition Friday.

Her passenger, Lucas Miller, 18, of Sonora, was taken to Sonora Regional Medical Center with minor injuries. He was treated and released Thursday.

The afternoon of the accident, Zahm had picked Miller up from Bret Harte High School and was taking him to Sierra Foothills Residential Care, an assisted living facility for developmentally disabled adults, the facility's director and administrator Dawn Sarto said.

Miller had recently moved into the 14-bed facility, where Zahm has worked for 27 years, Sarto said.

Miller kicked out his door and attempted to remove Zahm from the cab, Sarto said. He also assisted bystanders in trying to put out the blaze with fire extinguishers.

Zahm drove Highway 49 almost daily, Sarto said.

It's unclear what caused Zahm to swerve into the opposing traffic lane.

Sarto said Zahm might have lost consciousness while driving, but she was not aware of any health problems.

Miller told Sarto he and Zahm were talking in the car and she suddenly went quiet. Her head fell down and the car jerked left, Sarto said.

"She's a very good driver, so for her to swerve into the other lane, something extremely unusual happened," said Zahm's friend, Jan Opie.

Opie said she and Zahm have been friends since they met in sixth grade. Opie took Zahm in when her Mill Villa Road home was badly damaged in a fire in May 2011.

Opie said on Friday that she was not sure if anyone told Zahm that the Stantons died.

"She's got some severe injuries," Opie said. "She's got a long haul to go."

Sarto described Zahm as a "very caring, loving person" and said the news of the deaths will devastate her.

"It's a horrendous thing to happen and we are feeling so bad about the other family," she said.