EE WAS WORKING ON THE INSTALLATION OF A NEW BELT SET-UP ON #1 UNIT. HE BENT OVER TO PICK UP A BELT ROPE OFF THE GROUND WHEN A PIECE OF ROCK 4' X 5' X 3"" THICK FELL FROM THE MINE ROOF AND STRU CK HIM ACROSS THE BACK AND LEFT KNEE. BECAME A LOST TIME 3/3/04. THE PIECE OF ROCK FELL OUT BETWEEN PINS.