A big rig jack-knifed Thursday morning on the northbound 405 Freeway in Sherman Oaks, slowing the drive in the west San Fernando Valley.
The crash occurred about 4:40 a.m. near the connector ramp with the 101 Freeway.
Witnesses told the CHP that the truck driver ran from the crash and was last seen running toward the Ventura Freeway. Details about what led up to the crash were not immediately available.
The transition road from the northbound 405 Freeway to both directions of the 101 Freeway was closed and all lanes of the northbound 405 Freeway were stopped at about Ventura Boulevard, the CHP said.
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No injuries were immediately reported.