The crash also killed Walker's friend and financial adviser Roger Rodas, 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 (50 kilometers) 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' sports car dealership. Officials have not identified either person found in the car.
On Sunday, fans of 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.
