EE WAS ROOF BOLTING AND AS HE WAS INSERTING THE RESIN CARTRIDGE INTO THE HOLE, A SLAB OF ROCK FELL. SLAB STRUCK EE IN THE SHOULDER AND BACK, PINNING HIM AGAINST THE CONTROLS OF THE ROOF BOLTER. THE ROCK MEASURED 1.5-15"" THICK, 12-48"" WIDE AND 9' LONG.