One person died and another was hospitalized after a vehicle went tumbling down a hillside just east of Simi Valley Sunday evening, authorities said.

The crash occurred around 6:35 p.m. on Santa Susana Pass Road just east of Box Canyon Road.

According to California Highway Patrol, the car went flying off the road and rolled 300 feet downhill.

The driver was pinned inside the vehicle and had to be rescued by a Los Angeles Fire Department helicopter crew, authorities said. Emergency personnel transported the driver to a hospital in critical condition.

The passenger was pronounced dead at the scene.

“From my understanding, one of the parties called family, and the family ended up locating the vehicle,” Timothy Wren with CHP told KTLA.

The cause of the crash was under investigation.

Anyone with information is asked to call CHP at 805-553-0800.

Note: Authorities originally said two vehicles were involved in this incident and two people were injured.