Sophia Hutchins Cause of Death Released

Sophia Hutchins' cause of death has been released … and TMZ has learned it was blunt force trauma.

TMZ has obtained the death certificate released by the County of Los Angeles Medical Examiner ... which lists "Multiple Blunt Force Injuries" as the reason for her passing. Her manner of death was an accident, according to the certificate.

As we told you, Sophia tragically died earlier this month in an ATV accident near her longtime pal Caitlyn Jenner’s home in Malibu.

We're told she was riding along Caitlyn’s street when she hit the bumper of a moving car -- the crash sent the ATV off the shoulder, launching both it and Sophia 350 feet down into a ravine.

Our sources told us responders pronounced Sophia dead at the scene -- and cops quickly launched an investigation into speed being the cause of the deadly crash.