EE HAD FINISHED TAKING A CUT AND HAD MOVED THE CONT. MINER OUT ALLOWING THE ROOF BOLTER INTO THE CUT. BOLTERS STARTED BOLTING. INJURED ERE WALKED TO BOLTER TO TELL OPERATORS TO BE CAUTIOUS OF ROOF. AS HE STARTED TO WALK AWAY SOME LOOSE PIECES OF ROCK(@4' X 2' X 4"" THICK IN ALL) FELL FROM BETWEEN ROOF BOLTS AND STRUCK HIM ON RT SHOULDER, SCAPULA AREA.