Santa Barbara County firefighters responded Thursday morning to a tractor-trailer fire on Highway 101.
The cause of the fire is still unknown.
Capt. David Sadecki said a call came in around 7:02 a.m. Thursday reporting the fire on the southbound side of Highway 101 about five miles north of Los Alamos.
Three county fire engines responded to the scene, along with one engine from the Santa Maria Fire Department and a battalion chief.
A rig was towing two flatbed trailers loaded with flat cardboard boxes when the front trailer caught fire for unknown reasons, Sadecki said.
There were no injuries in the incident, which remains under investigation.