An early Monday morning crash involving a big rig and car resulted in the death of one and the closure of State Route 12 for several hours.

The crash happened just after 4:30 a.m. at Guard Road along SR-12, according to Stockton California Highway Patrol.

Investigators believe it was dense fog that brought the driver of the big rig, which was hauling a full load of walnuts, into the westbound lane of SR-12, prompting the 61-year-old Vacaville man to overcorrect back toward the eastbound lane he was traveling.

The big rig driver then lost control of the truck, causing the tractor as well as the double trailers to overturn across both lanes, according to investigators.

While the big rig was overturning, a 2002 Volvo, driven by a 73-year-old man, traveling westbound on the freeway collided with the rear of the trailer, investigators said.

The resulting collision sent the Volvo off the north roadway edge and into an irrigation ditch, according to investigators. The driver sustained fatal injuries, because of the collision.

The collision also covered the entire roadway with walnuts, forcing the closure of the freeway for several hours while Caltrans crews cleaned up the area.

Drugs and/or alcohol do not appear to have played a factor in the crash, according to CHP.