It happened just after 5 a.m. on eastbound Interstate 80, just west of El Portal Drive. That's where the big rig hit a guardrail, and rolled down an embankment.
Two other vehicles hit debris from the wreckage.
The big rig driver was killed. It's not clear if any of the other drivers were injured.
Two lanes were closed during the investigation and clean-up.
Sky7 over fatal crash in San Pablo- EB 80 near El Portal, truck down hillside, large piece of guardrail taken out. 2 right lanes remain blocked, 2 left lanes open, expect about a 10 minute delay. pic.twitter.com/fYzcrhfkdk— Alexis Smith (@AlexisABC7) July 15, 2019
**Sig Alert** issued for crash on EB 80 before El Portal in San Pablo - fatality investigation underway, 2 right lanes blocked, no ETO. pic.twitter.com/HyC1ospb5S— Alexis Smith (@AlexisABC7) July 15, 2019