Woods was in the Los Angeles area for his annual Genesis Invitational golf tournament at the Riviera Country Club, and was driving a courtesy car on the morning of the crash.
It happened near the hilly Palos Verdes peninsula, at the bottom of a stretch of road which has runaway truck ramps for drivers who lose control going downhill.
The section has become notorious for fatal accidents over the years.
"Apparently the first contact was with the center median, and from there (the car) crossed into the opposing lane of traffic, hit the curb, hit a tree, and there was several rollovers during that process," said Villanueva, who did not provide a cause of the crash.