EE WAS WALKING ALONG A COAL RIB IN THE 3-R LONGWALL SECTION, IN A CROSS-CUT ADJACENT TO THE STAGE LOADER, BETWEEN #3 AND #4 ENTRY, WHEN A PIECE OF COAL RIB APPROX 3'LONG X 1'WIDE FELL STRIKING HIM ON BACK OF RIGHT SHOULDER - CAUSED HIM TO FALL TWISTING HIS LOWER RT LEG.