The Los Angeles Country Coroner confirmed this in the final report issued Friday involving the death of Walker and his financial adviser Roger Rodas.
"For unknown reasons, the driver lost control of his vehicle, and the vehicle partially spun around," the report says.
The report also explains the actor's features were burned so badly he was unrecognizable and his body had several fractures. The coroner was only able to identify Rodas' body though dental records.
Though many people speculated a vehicle malfunction caused the crash, the report made no note to it.
The autopsy found no traces of drugs or alcohol in either bodies.