An employee was operating a rail king (equipment that moves rail cars) to couple two rail cars. The rail cars would not couple, so the employee bumped the rail cars and the front rail car started moving. The employee got off the rail king and attempted to get onto the moving rail car to set the brake. The employee slipped as he was getting onto the rail car and a wheel ran over his left foot amputating at least two toes. The employee was transported to the hospital where he underwent surgery and the left foot was amputated.