An employee was driving a hostler and transporting an intermodal container on a chassis to the back row of the yard. When he attempted to position the truck to reverse into the parking spot, the truck possibly jackknifed, causing the intermodal container to fall from the chassis and the hostler to raise up off the ground and then slam down again. The employee was bounced around inside the cab of the hostler, suffering a broken jaw, broken right elbow, broken rib, and contusion to the right knee.