THE MINER WAS MARKING THE FACE PRIOR TO DRILLING. THE BACK AND RIBS HAD BEEN WIRED AND BOLTED TOT HE FACE. THE FACE WAS INADEQUATELY SCALED. A ROCK CAME OUT OF THE FACE. IT KNOCKED OFF THE HAR D HAT CAUSING CUTS TO THE BACK OF THE HEAD, RIGHT SHOULDER, AND RIGHT ARM. AFTER FIRST AID THE CUTS WERE CLOSED W/STAPLES @ THE HOSPITAL. THE EMPLOYEE RETURNED TO WORK ON UNRESTRICTED DUTY W/