Actor Paul Walker's co-star Tyrese Gibson on the "Fast and the Furious" films pays his respects at memorial site. (James Barragan/Los Angeles Times.)

Actor Tyrese Gibson, Paul Walker's co-star on the "Fast and the Furious" films, pays his respects at the makeshift memorial site at the scene of the crash. (James Barragan/Los Angeles Times / December 1, 2013)

As a Santa Clarita charity event and car show was winding down Saturday, actor Paul Walker and friend Roger Rodas went for a ride in a red Porsche and never came back, a witness said.

Jim Torp heard a loud boom and said he knew in his heart his friends had been in an accident. The smoke from the crash was visible from Always Evolving, the automotive shop where car enthusiasts and supporters were still gathered – some thought it was just a fire on a nearby hill.

His son, Brandon Torp, 28, then grabbed a fire extinguisher and headed up the hill, followed by about 20 other workers, the elder Torp said.

PHOTOS: Celebrities react to the death of Paul Walker

"There was nothing they could do," he said.

Walker, 40, and his friend, whom Torp identified as Rodas, owner of Always Evolving, were killed about 3:30 p.m. in the single-vehicle crash. Walker was apparently the passenger in the red Porsche.

Torp said his son saw his two friends burn in the car before the Fire Department arrived.

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.

Officials at the scene held back a childhood friend of Walker from saving the actor’s body from the burning car, and firefighters had to pull Rodas’ young son away from the wreckage, said Jim Torp.

"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."

Sheriff's officials said speed may have been a factor in the single-vehicle crash, which occurred on Hercules Street, a normally quiet street with a 45 mph speed limit. The car knocked over a tree and a concrete lamp post.

The Porsche was badly burned and mangled. The cause of the crash remains under investigation, sheriff’s Deputy Kim Manatt told The Times.

The event was held in support of Walker’s organization Reach Out Worldwide, formed in 2010 as a quick response first-aid organization, and was one of many car shows Rodas helped put on each month, Torp said. Proceeds are to be donated to families affected by the typhoon in the Philippines and a tornado in Indiana, Torp said.

The parking lot of the shop had been full of high-performance cars, and the two were greeting people and shaking hands and enjoying themselves earlier in the afternoon, he said, adding that Walker was overwhelmed by the event's success.

“The saddest part was watching ... Paul Walker’s daughter break down,” Torp said.

When Rodas' wife and daughter arrived at the Always Evolving warehouse after the accident, he said he heard screaming through the doors after they learned of Rodas' death.

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."

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.

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 and 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 site of the fiery car crash where a makeshift memorial was growing. “Fast and Furious” memorabilia was placed alongside candles and flowers. One sign read, "Paul Walker Race in Heaven."

ALSO:

Paul Walker's death in car crash stuns Hollywood

Hollywood Christmas Parade brings many street closures

Man who died in San Pedro harbor was apparently trying to rescue others

Twitter: @Sam_Schaefer

Samantha.Schaefer@latimes.com