EMPLOYEE WAS OPERATING A DOUBLE BOOM LONG AIRDOXROOF BOLTER. HE WAS INSTALLING HIS FIRST BOLT INTHE FACE OF THE NUMBER NINE ENTRY WHEN A PIECE OF ROCK FELL OUT OF THE MINE ROOF STRIKING THE PROCTECTIVE CANOPY. AFTER THE ROCK HIT ON THE CANOPY IT FLIPPED OVER AND STRUCK THE EMPLOYEE ON THE UPPER LIP CAUSING A LACERATION REQUIRING 11 SUTURES TO CLOSE. TREATED AND RELEASED BACK.