LIVERMORE — A fire that began on a big rig spread to a hillside near the Altamont Pass early Friday and forced an hourslong closure to one direction of a freeway that lasted into the afternoon, the California Highway Patrol said.

All lanes on westbound Interstate 580 at the Altamont Pass are blocked Friday morning after due to a vehicle fire.According to firefighters, a big-rig caught fire in the westbound direction near Grant Line Road shortly before 6 a.

A big rig fire on the Altamont Pass east of Livermore early Friday morning spread to the nearby hillside, prompting the closure of westbound Interstate 580, according to the California Highway Patrol.