Walker and his friend and fellow fast-car enthusiast Roger Rodas died Saturday when the 2005 Porsche Carrera GT they were traveling in smashed into a light pole and tree.
The two had taken what was expected to be a brief drive away from a charity fundraiser and toy drive at Rodas' custom car shop in the Southern California community of Valencia, about 30 miles northwest of Los Angeles.
The crash happened on a street that forms an approximately 1-mile loop amid industrial office parks and is rimmed by hills and isolated from traffic, especially on weekends.
"It's well-known out here that that's a hot spot for street racers," California Highway Patrol Sgt. Rick Miler said. "It's a long stretch where, weekends, businesses are all closed and they feel like nobody's going to bother them up there."
The Los Angeles County Sheriff's Department is still investigating the accident but already has said speed was a factor. The posted limit was 45 mph.
Investigators are trying to determine how fast the car was traveling and what caused it to go out of control, including whether the driver was distracted or something in the road prompted him to swerve.
Walker's publicist said the action star was Rodas' passenger. Officials have not named either person found in the car. The bodies were so badly burned by the fire that engulfed the wreck that dental records will be needed to confirm their identities.
Walker and Rodas had bonded over their shared love of racing.
Rodas, 38, and Walker, 40, co-owned an auto racing team named after Rodas' shop, Always Evolving. Rodas was a financial adviser as well as a professional driver who competed in 10 Pirelli World Challenge GTS races in 2013, his first year on the circuit. He finished second in rookie of the year standings, circuit spokesman Dave Drimmie said.
Walker starred in all but one of the six "Fast & Furious" blockbusters. He had been on break from shooting the latest installment; Universal Pictures has not said what it plans to do with "Fast & Furious 7," currently slated for a July release.
On Monday, fans of Walker continued to gather at the crash site, leaving flowers and memorabilia from the movie franchise about fast cars that made him famous.
Coyle reported from New York. Associated Press researcher Barbara Sambriski in New York contributed to this report.
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