SAN MATEO, Calif. (KTVU) -- - Overnight rain and slick conditions likely contributed to a deadly crash early Saturday morning on southbound Highway 101 in San Mateo, authorities said.
The collision and subsequent CHP investigation shut down all, but one southbound lane.
A sigalert remained in effect, as authorities investigated the crash, and clear the debris.
At first, only southbound lane #5 was open.
Authorities then reopened lane #4 at about 7:45 a.m. However, it was unclear, on when all southbound lanes will be clear.
The CHP received the first call of a crash at about 3:15 a.m. Saturday.
As officers approached, they saw other vehicles were involved in the wreck.
One person died at the scene, while three other people in the crash, were taken to Stanford Medical Center.
One of the crash victims suffered major injuries, while the injuries of the other two survivors were said to be minor.
"It was raining earlier," said Sgt. Kalem Brock, California Highway Patrol. "It has since stopped. But with these wet roadways, and some of the speeds involved, it's a likely possibility that it played a factor."
Investigators also think that alcohol may have been another factor in the collision.