A deadly accident involving a motorcyclist caused a shutdown on Highway 84 in Livermore on Monday afternoon.
Officers said the motorcyclist might have run into two cars that had collided seconds earlier at Concannon Boulevard.
When emergency crews arrived about 12:45 p.m. they found the motorcyclist lying on the road.
They attempted to resuscitate the man, but he was pronounced dead at the scene.
All lanes of Highway 84 were closed as of about 3:30 p.m. Northbound traffic was being diverted onto Vineyard Avenue. Southbound traffic was being diverted onto Stanley Boulevard.
The cause of the accident was under investigation.