LOS ANGELES - Fans of "Fast & Furious" star Paul Walker created a makeshift memorial Sunday at the site where a car he was riding in crashed, killing the actor and a friend. The Los Angeles County Sheriff's Department says speed was a factor in the one-car crash in the community of Valencia, about 30 miles northwest of downtown Los Angeles. Deputies found a 2005 red Porsche Carrera GT engulfed in flames when they arrived Saturday afternoon. On Sunday, fans of Walker, 40, gathered to leave flowers, candles and memorabilia from the action film franchise. Walker's publicist said Sunday that the other person in the car was Roger Rodas, a friend of Walker's who owned a sport car dealership in Valencia. Ame Van Iden said the actor was the passenger, though the sheriff's department did not confirm that. The Porsche crashed into a light pole and tree and burst into flames. The downed light pole had a speed limit sign of 45 mph. Sheriff's deputy Peter Gomez said investigators are working 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.