Speed may have been a factor in the crash, which occurred about 3:30 p.m. on Hercules Street, a normally quiet road with a 45-mph speed limit, authorities said. Walker was apparently the passenger in the 2005 red Porsche Carrera GT.
The four-lane road up the hilly street has signs warning drivers to slow down as they approach an uphill curve near the site of the accident.
Photos: Paul Walker, 1973-2013
The fiery crash left charred trees in the secluded area near a business park, and a burned smell lingered in the air Sunday. The car, which was reduced to an ashen hulk, had toppled a tree and a concrete lamp post, which crews from Southern California Edison removed Sunday. Looping tire tracks were visible on the asphalt nearby.
Investigators are looking at whether the tire tracks are related to the crash, but the investigation is ongoing, said Sheriff’s Deputy Peter Gomez. There probably will not be an update on the investigation until Monday, he said.
Because of the condition of the bodies, which were badly burned, dental records will be used to positively identify the victims, said Los Angeles County coroner's investigator Dana Bee. Autopsies have not been scheduled.
PHOTOS: Celebrities react to the death of Paul Walker
A video taken moments after the accident shows black smoke billowing from the crumpled red Porsche, which caught fire, and debris scattered about the roadway.
"The car is in half. I can't tell if there is someone in there," one person on the video is heard saying.
Seconds later comes an answer: "Yes, there is someone in there." At least one person heard on the video expresses concern that the burning car could explode.
Torp said his son saw his two friends burn in the car before the Fire Department arrived. Officials at the scene held back a childhood friend of Walker from pulling his body from the burning car, and firefighters had to pull Rodas’ young son away from the wreckage, Jim Torp said.
Eduardo Luna, who owns the warehouse across from where the event was held, saw the Porsche leave the parking lot moments before the crash. Ten minutes later, he heard about the accident and ran down to Hercules Street, where he saw the car in flames.
"They just didn't want to believe this happened," Torp told fans and media at the crash site on Sunday. "It was 'Fast and the Furious,' that's what it is. Both race car enthusiasts, both loved speed, both knew how to handle cars, and this had to happen."
Walker was in good spirits earlier in the afternoon and overwhelmed by the event’s success, Torp said. The parking lot of the shop had been full of high-performance cars, and he and Rodas were greeting people, shaking hands and enjoying themselves.
Reach Out Worldwide was formed in 2010 as a quick-response first-aid organization, and the event was one of many car shows Rodas helped put on each month, Torp said. Proceeds were to be donated to families affected by the typhoon in the Philippines and a tornado in Indiana, Torp said.
When Rodas' wife and young daughter arrived at the Always Evolving warehouse after the accident, he said he heard screaming through the doors after they learned of Rodas' death.
“The saddest part was watching ... Paul Walker’s daughter break down,” Torp said.
Rodas, 38, was active in philanthropy and supported several charities through his racing. He competed in 10 Pirelli World Challenge GTS races in 2013, according to the racing organization. Torp, who with his son has worked with Always Evolving for several years, described Rodas as a compassionate, fun man who cared deeply about others, and "loved his American cars as much as he loved his $500,000 cars."
"They died doing what they enjoy doing," he said. "Two close friends died together right next to a church. They're both with God."
Walker's death was confirmed by a statement posted to his Twitter account Saturday.
“It is with a truly heavy heart that we must confirm that Paul Walker passed away today in a tragic car accident while attending a charity event for his organization Reach Out Worldwide,” the statement said. “He was a passenger in a friend's car, in which both lost their lives. We appreciate your patience as we too are stunned and saddened beyond belief by this news.”
At the time of his death, the “Fast & Furious” star, who also appeared in "Pleasantville" and "Varsity Blues," was working on the seventh film of the franchise.
Dozens of fans gathered in Valencia early Sunday at the crash site, where a makeshift memorial was growing. “Fast & Furious” memorabilia was placed alongside candles and flowers. One sign read, "Paul Walker Race in Heaven."
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