A big rig driver was killed in a crash along Interstate 580 west of Tracy early Tuesday morning, according to authorities.

California Highway Patrol says, just after 1:30 a.m., a Volvo big rig crashed into another big rig as it approached stopped traffic on the westbound side of the freeway east of International Parkway.

The Volvo big rig driver was pinned by the crash and both lanes were blocked.

Medics pronounced the Volvo big rig driver dead at the scene, CHP says.

Exactly what led up to the crash is under investigation.

Lanes along westbound I-580 were blocked through the early morning hours. All lanes were reopened just after 10 a.m.