AFTER BOLTING THE FACE OF NUMBER 6 ENTRY, TWO WORKERS WERE SITTING AT THE BACK OF THE ROOF BOLTER WAITING FOR THE CONTINUOUS MINER TO FINISH CUTTING #5 LEFT. A ROCK MEASURING 12' X 3.5' X O"" TO 7"" THICK FELL AND BROKE OVER THE TRAM CANOPY OF THE MACHINE. ONE OF THE PIECES STRUCK EE ON THE SHIN CAUSING A LACERATION AND PARTIAL AVULSION THAT REQUIRED SUTURES TO CLOSE.