EMPLOYEE & ANOTHER CO-WORKER WERE IN THE PROCESS OF REPAIRING A BLOCK WALL STOPPING WHEN A PIECE OF ROCK FELL FROM THE ROOF STRIKING EMPLOYEE ON THE BACK OF HIS NECK. CAUSE OF THIS INJURY WAS SAFETY AWARENESS & INEXPERIENCE. RULES/REGULATIONS NOT A FACTOR; PROTECTIVE EQUIPMENT NOT A FACTOR; MINER KNOWLEDGE COULD BE A FACTOR; MINING EQUIPMENT/SYSTEMS NOT A FACTOR.