Mira Tijerin, of San Diego, was pronounced dead early Saturday at a collision scene after she lost control of her Nissan pick-up and rolled 300 feet down an embankment off northbound Interstate-5 about 30 minutes north of Santa Clarita.

For reasons still under investigation, Tijerin spun out near Vista del Lago, around 3 a.m. careened across freeway lanes, broke through the metal guard rail and crashed down the embankment, according to a California Highway Patrol report. She was thrown from the truck.

The report indicated Tijerin and two of the truck’s three passengers were not wearing seatbelts.

The three San Diego and Los Angeles passengers in the truck were taken to Henry Mayo Newhall Memorial Hospital in Valencia and Providence Holy Cross Medical Center in Mission Hills, for injuries such as fractured spine, back and shoulder pain, the report read.

CHP Officer Curtis Rhoades is investigating the collision.