Fans of ''Fast & Furious'' star Paul Walker erected a makeshift memorial near the site of his fatal automobile crash, as investigators worked to determine the cause of the fiery weekend wreck that also claimed the life of his friend.
The Los Angeles County Sheriff's Department said speed was a factor in Saturday's one-car crash, though it will take time to determine how fast the car was going.
Roger Rodas, Paul Walker's friend and financial adviser, also died, according to Walker's publicist, Ame Van Iden. She said Walker was a passenger in the 2005 red Porsche Carrera GT when they drove away from a fundraiser in the community of Valencia, about 30 miles northwest of downtown Los Angeles.
Sheriff's deputies found the car engulfed in flames when they arrived at the site of the crash, near the fundraiser at Rodas' sport car dealership. Officials have not identified either person found in the car.
Because Paul Walker is so closely associated with the underground culture of street racing portrayed in the popular film franchise, the accident had an eerie quality - a tragic end for a Hollywood hero of speed.
On Sunday, fans of Paul Walker, 40, gathered to leave flowers, candles and memorabilia from the action movies. His ''Fast & Furious'' co-star Tyrese Gibson broke down when he visited the crash site.
''Paul Walker is the heartbeat of this franchise and we're gonna see to it that his energy and presence lives on forever,'' Gibson later posted on his Instagram account.
Sheriff's deputy Peter Gomez said investigators were 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.
After the Porsche crashed into a light pole and tree, it burst into flames. The downed light pole had a speed limit sign of 45 mph (72 kph).
Paul Walker rode the ''Fast & Furious'' franchise to fame, starring in all but one of the six action blockbusters, beginning with the first film in 2001. He had been on break from shooting the seventh installment; production began in September and while much of the film has been shot, it's incomplete.
Universal Pictures has not said what it plans to do with ''Fast & Furious 7,'' which currently is slated for release in July.
Paul Walker and Rodas had thrown