EMPLOYEE GOT OUT OF SHUTTLE CAR & PRECEEDED TO HELP WATCH MINER CABLE WHILE THE MINER CHANGED PLACES. EMPLOYEE WAS STRUCK ON THE HARD HAT BY A PIECE OF DRAW ROCK. EMPLOYEE WAS ASKED HOW BIG TH E ROCK WAS, REPLIED ""I DIDN'T LOOK FOR IT"". CEILING AT THE AREA 9', ROCK KNOCKED EMPLOYEE DOWN.