EMPLOYEE WAS MARKING OFF BOLT HOLE. A PIECE OF ROCK FELL, STRIKING HIM ON TOP OF HIS HARD HAT, PUSHING IT FORWARD DOWN ON HIS SAFETY GLASSES AND CAUSING A HAIRLINE FRACTURE OF THE NOSE. THIS EMPLOYEE WORKS A 4 ON AND 4 OFF SCHEDULE. THE 20TH WAS HIS FIFTH DAY AND HE WILL BE OFF UNTIL 4/24/04.