EMPLOYEE WAS STANDING ON A LARGE ROCK FLAGGING THE FRONTEND LOADER TO BUILD A RAMP FOR THE ROCK DRILL, WHEN THE ROCK HE WAS STANDING ON WAS HIT WITH THE TIRE OF THE MACHINE, CAUSING THE EMPLOY EE TO CATAPULT APPROX. 8' IN THE AIR. HE SUSTAINED A BROKEN COLLAR BONE, BROKEN RIB AND BRUISED LUNG.