EE HAD JUST TRAMMED BOLTER INTO POSITION AND WAS SETTING TRS SUPPORT, WHEN A LARGE PIECE OF ROOF ROCK FELL OUT OF ROOF. ROCK STRUCK TRS BEAM, THEN FELL ONTO OPERATOR'S CANOPY, THEN FELL ONTO EE, STRIKING HIM ON THE BACK. ROCK SETTLED DOWN ON RIB AND CANOPY. EE MAY MISS 2-3 WEEKS WORK.