Multiple lanes on the westbound 91 Freeway in Yorba Linda are closed Monday morning after a semi-truck crash.
The California Highway Patrol has issued a Sig Alert on the 91 freeway at the 241 Freeway. The closure is causing a backup up to Main Street in Corona.
KCAL News has also issued a Next Traffic Alert to warn drivers about the impact on their morning commute.
It is unclear what led up to the crash.
Drivers are urged to use alternate routes and plan for traffic delays.