His friend Roger Rodas, who witnesses say was driving the vehicle that crashed and killed both men on Saturday, died from multiple traumatic injuries.
The Los Angeles County Department of Medical Examiner-Coroner conducted an autopsy on both bodies on Tuesday. Both deaths were ruled accidents. A toxicology analysis is still pending and could take weeks to complete.
Walker and Rodas died after a special-edition Porsche crashed into a light pole, two trees and a sign noting the street's 45 m.p.h. speed limit.
An investigator says their car was going at least 90 m.p.h. when it crashed.
With news of the star's passing, the Fast & Furious 7 actor's cast mates will halt filming the latest movie in the hit franchise.
"Right now, all of us at Universal are dedicated to providing support to Paul's immediate family and our extended Fast & Furious family of cast, crew and filmmakers," Universal said in a statement to PEOPLE on Wednesday. "At this time we feel it is our responsibility to shut down production on Fast & Furious 7 for a period of time so we can assess all options available to move forward with the franchise. We are committed to keeping Fast & Furious fans informed, and we will provide further information to them when we have it. Until then, we know they join us in mourning the passing of our dear friend Paul Walker."
Walker was participating in the Reach Out WorldWide charity car show before he died. Friends told PEOPLE he was excited about the toys his charity was collecting for children affected by Typhoon Haiyan and tornadoes in the Midwestern U.S.
He is survived by his 15-year-old daughter Meadow Rain.