Six people were injured in a single-vehicle rollover crash on a foggy Thursday morning near Santa Maria, and authorities declared a a mass casualty incident. 

Emergency personnel from the Santa Barbara County Fire Department and California Highway Patrol responded at approximately 5:50 a.m. to Foxen Canyon Road after a vehicle rolled over, fire Capt. Scott Safechuck said. 

The crash left two patients with major injuries, two with moderate injuries and two with minor injuries leading to a request for three American Medical Response ambulances, Safechuck added.

The four men and two women were taken to Marian Regional Medical Center, he said.

Foggy conditions were reported in the area Thursday morning, Safechuck said.

A damaged power pole prompted a request for a Pacific Gas & Electric Co. crew to respond to the scene to fix the utility equipment. 

CHP officers from the Santa Maria area were investigating the circumstances that led to the crash.

Additional information was not immediately available.