A big rig jack-knifed Thursday morning on the northbound San Diego (405) Freeway in Sherman Oaks, blocking all lanes of traffic until further notice.
The crash occurred about 4:40 a.m. near the connector ramp with the Ventura (101) Freeway, according to the California Highway Patrol.
Witnesses told the CHP that the truck driver ran from the accident and was last seen running toward the Ventura Freeway.
The transition road from the northbound San Diego Freeway to both directions of the Ventura Freeway was closed and all lanes of the northbound 405 Freeway were stopped at about Ventura Boulevard, the CHP said.
No injuries were immediately reported.