Investigators have said from the get-go that speed was a factor in the Paul Walker crash on Saturday, Nov. 30, which claimed the actor's life and the life of his friend Roger Rodas. Now, sources say that the pair was driving at least 90 mph.

It's reported that the high-performance vehicle, which has been described as hard to handle and sensitive to any sort of grooves in the street, hit two trees, a light pole and a speed limit sign, which posted a 45 mph limit. The theory that a second car was involved as part of a drag race has since been exhausted and dismissed.

Los Angeles County Sheriff's detective Jeff Maag estimated that Rodas was doing double the posted speed limit. He said the driver "was doing well over 45 – [it's] fair to say at least twice that."

The investigation should carry on for at least another week and possibly longer so that officials can determine the rate of speed and if manufacturer defects or mechanical issues also factored into the crash. A steering fluid leak has been suggested.

Since the car was badly mangled, determining factors can take some time to sort out. The investigators also need to locate the car's black box.

Yes, the car is believed to have had one of those, which can, according to Maag, "give us the speed, whether they were wearing their seat belts, all kinds of information 25 seconds before the collision and 5 seconds after."

The autopsies have been delayed while the coroner waits for dental records.

Antonio Holmes knew both victims and told PEOPLE that he was a first responder, trying to help put out the blaze with fire extinguishers. He confirmed that Rodas was driving and Walker was in the passenger's seat with his seat belt fastened.

A car enthusiast, Holmes also believes that a mechanical failure is at fault.

"For that car to disintegrate the way it did, speed, of course [was a factor], but something went wrong and it put them at an angle to the curb," Holmes said. "There's not a shadow of a doubt in my mind, it wasn't driver error."

Whatever the cause, it remains a tragic event.