Six Union Pacific Railroad cars derailed approximately 15 miles south of Dunsmuir on Tuesday. The six cars were empty and no injuries were reported, and no spills occurred. The cause of the derailment is under investigation, said Aaron Hunt, Union Pacific media spokesperson.

The cars derailed at 6:30 p.m. when the train was hauling agriculture and automotive freight en route from Roseville, Calif. to Portland, Ore.

“The empty cars derailed upright and were leaning against a mountain,”  Hunt explained. The derailment did not result in any environmental damage, and no materials made contact with the Sacramento River, he added.

Union Pacific personnel used equipment called side booms to lift the cars up and re-rail them. The rail opened back up by 10 p.m. that same night, Hunt said.

“The investigation into the cause will be ongoing,” Hunt stated. He noted that mudslides and weather conditions were not factors in the derailment.