"We were collecting toys for the Indiana tornado victims and the Philippine [typhoon] victims," says Jim Torp, who attended the event held by Always Evolving, a Valencia, Calif.-based automotive company. "There were dozens of high-end race cars and custom-built cars on display."
As the car show was winding down, Walker, whose 15-year-old daughter Meadow Rain also was at the event, got into a red 2005 Porsche Carrera GT with the car's driver, Always Evolving owner Roger Rodas.
"Roger was definitely behind the wheel," says Torp, a Santa Clarita, Calif., electrician who was an acquaintance of Rodas. "Roger slowly drove it out – he didn't take off recklessly. There were children around, after all. They were only gone for five or ten minutes and never came back."
Was Speed a Factor?"The crash happened right behind the Always Evolving warehouse, just one street over in a commercial area," Torp says.
"Suddenly I heard a loud bang in the distance," he continues. "There was billowing black smoke in the distance. When I saw that, I felt in my heart that something was tragically wrong."
While a Los Angeles County sheriff's statement said that "speed was a factor" in the accident, another official would not say so definitively.
Courtesy of Always Evolving
"It looks like speed could've been a factor, but we haven't made an official determination for the cause of the accident, which will take some time," Lt. John Rush of the Santa Clarita Sheriff's Station tells PEOPLE.
Chaotic SceneWhen Torp arrived at the scene of the accident, he says the Porsche was "totally unrecognizable and completely engulfed in flames."
"The scene was chaotic," he says. "There were probably about 20 friends and employees, screaming and crying, who had grabbed fire extinguishers and had been doing what they could to rescue the guys. The fire department and sheriffs had just arrived as well, and they were trying to secure the scene."
Another eyewitness, who did not want to be named, tells PEOPLE he arrived at the crash site within seconds of seeing black smoke.
"[The car] was engulfed in flames," the witness says. "People were trying to get extinguishers but it was just too much. We didn't know if it was going to explode. You couldn't get into it at all. It was about half a minute ... and basically it was engulfed in flames."
Firefighters arrived within minutes, the witness says: "The fire department started dousing [the car]. They did put it out pretty fast with their equipment but it was just too late."
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Experienced DriversTorp says he's in shock after the accident partly because Rodas and Walker were "very experienced and professional race car drivers."
"It was clear the car had hit two trees then finally hit a street lamppost," he says. "Parts of the car were strewn everywhere on the street, as far as 150 feet. I didn't see any skid marks. Where the car had crashed was on a long straightaway. How fast they were going, I don't know."
Adds Torp: "Roger was not a reckless guy. He was a family man. He has a wife and two young children. He never did anything careless."
Reporting by KEN LEE, MELODY CHIU and ELAINE ARADILLAS