The Los Angeles County Sheriff's Department is still investigating the cause of the car accident that killed actor Paul Walker and his friend Roger Rodas. The two men were involved in a car accident on Saturday, Nov. 30. 

Walker and Rodas had been attending a charity event in Santa Clarita, Calif. when they decided to take a red Porsche for a test drive. According to witnesses less than ten minutes after the car pulled out of the parking lot, it lost control and crashed into a tree. A minute later the car exploded. According to reports Walker was in the passenger seat when the accident occurred.

There have been several reports that car was traveling about 90-mph at the time of the accident but authorities have not been able to verify this information. Witnesses claim they saw "a single speeding car," the Los Angeles Times reports.

"The only eyewitness to come forward saw a single speeding car," Capt. Mike Parker said.

Parker said the police department did hear rumors that Walker and Rodas were in a street race but that information hasn't been verified either. One of the witnesses to come forward, Jim Torp, said he heard a loud boom following the accident and knew Walker and Rodas had been in an accident. Other people thought the smoke might have been the result of a fire on a nearby hill and ran over with fire extinguishers to help.

"There was nothing they could do," he said adding that his 28-year-old son Brandon ran over to help.

Reportedly fire fighters and police had to pull people away from the car including Rodas' 8-year-old son because it was too dangerous.

"They just didn't want to believe this happened," Torp told fans and the media at the crash site. "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."