A big rig loaded with hay caught fire Thursday afternoon.

According to the California Highway Patrol , the hay truck with double trailers was westbound on Interstate 8 near Brock Research Center Road at about 12:45 p.m. when the fire was reported. Initial reports are that several hay bales fell from the big rig and when stopped on the shoulder of the freeway both trailers and their load of hay were fully engulfed in flames. The Imperial County Fire Department responded. One lane of the westbound freeway was closed until approximately 6:30 p.m. and traffic was reported backed up for several miles at one time. While the traffic lane was open the shoulder remained closed. The incident remains under investigation.