LOS ANGELES (AP) -- Investigators sought to determine the cause of a fiery crash that killed "Fast & Furious" star Paul Walker while the 40-year-old actor's fans erected a makeshift memorial Sunday near where the Porsche he was riding in smashed into a light pole and tree.
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.
Because Walker is so closely associated with the underground culture of street racing portrayed in the popular "Fast & Furious" film franchise, the fatal accident had an eerie quality - a tragic end for a Hollywood hero of speed.
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 car when the two drove away in a 2005 red Porsche Carrera GT 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.
On Sunday, fans of Walker, 40, gathered to leave flowers, candles and memorabilia from the action movies.
Walker is "gone but he'll never be forgotten because there are so many people that look up to him," Joel Perez, 23, told the Los Angeles Times at the memorial.
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.
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.
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.
Walker and Rodas had attended a fundraiser benefiting victims of the recent typhoon in the Philippines. The event was held by Walker's Reach Out Worldwide, a charity he founded in 2010 to aid victims of natural disasters.
The fundraiser and toy drive took place at Rodas' custom car shop, Always Evolving. Attendees rushed to the nearby crash to try to put out the flames with fire extinguishers.
Bill Townsend, who attended the event, told AP Radio that Walker appeared very happy at the fundraiser.
"He was smiling at everybody, just tickled that all these people came out to support this charity," Townsend said. "He was doing what he loved. He was surrounded by friends, surrounded by cars."
Walker left behind two completed films. He stars in the upcoming Hurricane Katrina drama "Hours," which Lionsgate's Pantelion Films is to release Dec. 13. He also stars in "Brick Mansions," a remake of the French action film "District B13" that Relativity plans to release next year.
His "Fast & Furious" co-stars reacted in shock the actor's death. Vin Diesel posted a photograph of him and Walker arm-in-arm on Instagram with the message: "I am absolutely speechless." Lucadris said on Twitter: "Wherever you blessed your presence you always left a mark, we were like brothers."
Walker is survived by his 15-year-old daughter.
Paul Walker, the star of the "Fast and Furious" movie series, died Saturday in a car crash that killed one other person north of Los Angeles, his publicist said. He was 40.
Walker died Saturday afternoon, Ame Van Iden told The Associated Press.
A statement on the actor's Facebook page said he was a passenger in a friend's car, and that Walker was in the area to attend a charity event for his organization Reach Out Worldwide.
"We ... are stunned and saddened beyond belief by this news," the statement said.
The Los Angeles County Sheriff's Department said that deputies found a car engulfed in flames when they responded to a report of a collision in the community of Valencia. Two people who were found in the car were pronounced dead at the scene.
The Santa Clarita Signal reports a red Porsche crashed into a light pole and tree and burst into flames.
Bing: More about Paul Walker
Walker was working on "Fast & Furious 7" at the time of his death. He also starred in the suspense drama, "Hours," which is set for release this month.
Walker rode the "Fast & Furious" franchise to stardom, starring in all but one of the six action blockbusters, beginning with the first film in 2001. The blond-haired, blue-eyed Los Angeles-native brought California surfer good-looks and an easy, warm charm to the popular street-racing series.
"All of us at Universal are heartbroken," Universal Pictures said in a statement. "Paul was truly one of the most beloved and respected members of our studio family for 14 years, and this loss is devastating to us, to everyone involved with the 'Fast and Furious' films, and to countless fans."
The son of a fashion model and a sewer contractor, Walker grew up in a working class, Mormon Los Angeles household. The oldest of five siblings, Walker's mother began taking him to auditions as a toddler. He was a child model beginning at the age of 2.
Walker has said the early induction to show business wasn't to start him on a career path, but as a way to help provide for the family.
After a string of TV roles as a child in the '80s, Walker made his feature film debut in the 1998 comedy "Meet the Deedles." Supporting roles in the films "Pleasantville," ''Varsity Blues" and "She's All That" followed.
His performance in the 2000 thriller "The Skulls" caught the eye of producer Neal H. Moritz, who cast him in "The Fast and the Furious" as undercover police officer Brian O'Conner. Adapted from a Vibe magazine article about underground street races, the film became an unexpected hit.
In the sequel, "2 Fast 2 Furious," Walker moved to center stage with his co-star Vin Diesel momentarily dropping out. Walker, a self-described "gearhead," kept his character's sports car from the film.
Walker starred in other films, including the crime thriller "Running Scared," the Antarctic adventure "Eight Below" and the heist film "Takers." Though his stardom didn't make as much of an impact outside the "Fast & Furious" series, Walker continually drew praise from his co-stars and directors as a kind-hearted and eager collaborator.
And "Fast & Furious" proved unusually enduring. Released in May, "Fast & Furious 6" was the most lucrative of them all, grossing more than $788 million worldwide. The seventh installment began shooting in September, with a release planned for July.
"Your humble spirit was felt from the start," said Ludacris, Walker's "Fast & Furious" co-star, on Twitter. "Wherever you blessed your presence you always left a mark, we were like brothers."
Walker is survived by his 15-year-old daughter.
Copyright 2015 by The Associated Press. All Rights Reserved.