EL CAJON, Calif. — A woman was killed Friday in El Cajon Friday after driving off the road and striking a tree, the California Highway Patrol announced.

The crash happed around 4:30 p.m. on April 14 when a 67-year-old woman driving a Nissan Frontier eastbound on Willow Glen Drive, east of Hillsdale Road, was approaching a curve in the road.

For reasons still under investigation, the woman veered to the right and drove off of the roadway, where she struck a tree near 1919 Willow Glen Drive, CHP Public Information Officer Jared Grieshaber said in a news release.

The woman was found unconscious at the scene of the crash, according to CHP. She was transported to Sharp Memorial Hospital by paramedics, where she was later pronounced dead.

The circumstances that led to the crash are still under investigation. It is not yet known if drugs or alcohol were a factor, CHP said.

No other vehicles were involved in the crash.

The identity of the woman has not yet been publicly released by the San Diego County Medical Examiner’s Office.