ALONG WITH ANOTHER EMPLOYEE, HE WAS CLEANING OUT IMPACTED DIRT BUILDUP FROM THE INSIDE OF THE HOPPER. AS HE WAS CHIPPING AWAY WITH A PNEUMATIC CHIPPER TO CLEAR BUILDUP INSIDE THE HOPPER, A LARGE PIECE BROKE LOOSE AND PUSHED HIM BACK. IT HIT THE BACK OF HIS HEAD. HE FELL BACKWARDS AND WAS KNOCKED UNCONSCIOUS. REGAINING CONSCIOUSNESS, HE WAS DISORIENTED. X-RAYS NEGATIVE.