The Porsche in which actor Paul Walker and his friends were killed Saturday was traveling alone at a high rate of speed Saturday when it crashed in a fiery collision with two trees and a lamp post that left the car as little more than rubble, sheriff's officials said Monday.

"No eyewitness has contacted the Los Angeles County Sheriff's Department to say there was a second vehicle," a statement from the Sheriff's Department says, seeming to counter reports earlier today that the Porsche may have been drag-racing with another vehicle when the crash occurred.

A California Highway Patrol officer says the Rye Canyon Loop area of the Valencia Industrial Center where "Fast & Furious" star and his friend and financial adviser Roger Rodas died in a car crash is known to attract street racers.

The street where the crash happened forms a loop amid commercial buildings that sees little traffic, especially on weekends.

California Highway Patrol Sgt. Rick Miler calls the neighborhood "a hot spot for street racers."

Walker's publicist, Ame Van Iden, said Walker was a passenger in the 2005 red Porsche Carrera GT when they drove away from a fundraiser at Rodas business, Always Evolving Precision Motors, on Constellation Road in the Rye Canyon Loop.

Sheriff's deputies found the car engulfed in flames when they arrived at the site of the crash. Neither person in the vehicle has yet been officially identified. Los Angeles County Coroner's officials say an autopsy will be done on Walker's body.

Because 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 Monday, fans of Walker, 40, continued to gather at the site of the crash at Kelly Johnson Parkway and Hercules Street, leaving flowers and memorabilia from the movie franchise about fast cars that made him famous. His "Fast & Furious" co-star Tyrese Gibson broke down when he visited the crash site.

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.

Walker had spent time in Conyers in 2010 for the fifth installment, "Fast Five," which made its stateside shooting base in Rockdale.

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. Scenes shot in Atlanta included a funeral scene at the Historic Oakland Cemetary and scenes shot at a rock quarry in Stockbridge.

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 thrown a fundraiser benefiting victims of the recent typhoon in the Philippines. The event was held by Reach Out Worldwide, a charity Walker founded in 2010 to aid victims of natural disasters.

The fundraiser and toy drive took place at Rodas' custom car shop, Always Evolving, in an area of warehouses and office parks. Rodas, 38, and Walker co-owned an auto racing team. Rodas competed in 10 Pirelli World Challenge GTS races this year, the racing organization said in a statement.

Attendees rushed to the crash, which was nearby but out of sight, to try to put out the flames with fire extinguishers.

One attendee of the event, Jim Torp, said he heard the loud sound of a car's engine revving and then an explosion. Walker and Rodas planned a quick ride, Torp said.

"The last words Paul said to anybody were, 'Hey, I'll be back in five minutes. All right?' And that was it," according to Torp.

Torp said Rodas had a young son, whom he tried to stop from running to the accident scene, but could not catch him in time.

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.

He is survived by his 15-year-old daughter.

Courtesy of The Santa Clarita Signal and wire services.