Abstract: At approximately 12:55 p.m. on July 9, 2004, Employee #1, a tech for KVS Transportation Inc., was working with fellow crew members at 3-8R Stevens Zone at Occidental Elk Hills. He and his crew were cleaning petroleum tanks. The crew was in the process of unhooking a trailer from its pick-up. Employee #1 operated the trailer hitch in the down position. The trailer hitches hang up on the ball. The supervisor said he would jump on the truck bumper to help release the hitch. He told employee #1 to make sure his hands were clear. The supervisor jumped on the bumper, the hitch came free of the ball. However, employee #1 injured his left thumb.