The woman rolled her vehicle off the side of state Route 94 near the College Avenue offramp at 2:39 a.m. Firefighters used the jaws of life to get the woman out of the car and performed CPR on her for several minutes.
She was taken to the hospital, where she was pronounced dead just before 5 a.m.
The impact of the crash tore the engine from the car's hood, which started a small brush fire along the fence where the car came to a stop. Firefighters quickly put the fire out.
The College Avenue off-ramp to Route 94 was closed during the investigation but reopened at about 4:45 a.m.
Investigators had not determined if speed or drugs or alcohol contributed to the single-car crash