An overnight big rig crash and fire forced the closure of northbound 101 just south of San Luis Obispo early Thursday morning.
No injuries were reported.
"For unknown reasons the driver allowed the vehicle to travel into the center median and collide with the guardrail," the CHP said in an update via social media. "The vehicle then struck the concrete bridge overcrossing causing major damage."
The vehicle came to rest hanging from the over-crossing over Higuera Street.
The CHP, Cal Trans, and Cal Fire all worked on the scene following the crash as traffic was diverted onto South Higuera.
As the morning commute began, traffic was still affected as crews worked to remove debris from the roadway. Northbound 101 traffic was slow Thursday morning from the South Higuera exit into Pismo Beach.
Ontario Road, which crosses under Highway 101 at the point of the crash, remained closed late Thursday morning as inspectors determined whether its safe for traffic to pass under the structure.