EMPLOYEE WAS ASSISTING MECHANIC IN CHANGING OUT ELECTRIC PUMP MOTOR ON TWIN HEAD FLETCHER ROOF BOLTER, LEFT HAND WAS RESTING ON ROOF BOLTER WHEN A PIECE OF ROCK FELL FROM THE ROOF STRIKING EMP LOYEE ON HIS LEFT HAND. EMPLOYEE SUSTAINED LACERATIONS AND FRACTURES TO HIS LEFT HAND, EMPLOYEE WAS WEARING METACARPAL GLOVES AT THE TIME OF THE ACCIDENT.