EE WAS USING A 988 CAT LOADER TO SELECT ROCKS FROM A PILE ABOUT 15 FEET TALL. WHILE RETURNING TO THE PILE AFTER SETTING ASIDE ONE OF THE ROCKS. A ROCK ROLLED DOWN THE PILE AND HIT THE LOADER B UCKET WHICH WAS ABOUT A FOOT ABOVE THE FLOOR. WHEN THE ROCK MADE CONTACT WITH THE BUCKET IT JARRED THE OPERATOR AND INJURED HIS NECK.