EMPLOYEE WAS WORKING APPROXIMATELY 75 FT OUT BY THE FACE PIVKING UP TOOLS AND LOADING THEM INTO MUCK CAR TO BE REMOVED PRIOR TO SHOOTING THE FACE. THE REMAINDER OF THE CREW WAS CHARGING DRILL HOLES IN THE FACE WITH EXPLOSIVES. THE CREW AT THE FACE HEARD A LOUD NOISE, WHEN THEY WENT TO INVESTIGATE THEY FOUND INJURED PINNED UNDER A ROCK 8'6"" X 22"" X 22"" THAT HAD FALLEN OUT OF RIB.