EE WAS STANDING IN FRONT OF PARKED C/M, HANGING THE REMOTE CONTROL BOX FROM ROOF. A ROOF BOLTING MACHING WAS MOVING ACROSS THE SECTION. ITS TRAILING CABLE WAS LODGED BEHIND THE WATER BOX & WOULD NOT ALLOW THE CABLE TO UNWIND. CABLE TIGHTENED & JERKED FROM THE HOOKS IN ROOF. CABLE STRUCK EE ON THE R. SIDE OF HEAD & KNOCKED HIM TO MINE FLOOR. EE WAS UNCONSCIOUS APPROX. 12 HRS.