SECTION SUPERVISOR WAS CHECKING WITH BOLTING CREW GIVING INSTRUCTIONS OF MINING CYCLE, LOCATION WAS #2 ENTRY AT FACE OF PANEL ROOMS. AS HE WAS LEAVING BOLTER LT. SIDE OPERATOR, HE TOOK ABOUT 2 STEPS AND A PIECE OF BLACK SHALE FELL FROM ALONG THE RIB & ROOF AREA WHICH MEASURED 3'WIDE X 6'LONG X 0-6""THICK. IT FELL FROM ABOUT 2'UP THE TOP WAS 8'TALL. ROCK STRUCK HIS HEAD, NECK, BACK