A FALL OF ROOF OCCURRED IN THE 1ST N.E. SUB MAINS XCUT 7 SPAD #2-20 FROM #6 ENTRY TO #7 ENTRY LENGTH 75, WIDTH 18', THICKNESS 8'. SUPPORT USED IN THE AREA WAS 6' TENSION REBAR BOLTS, YEILD PRO PS, & CRIBS. APPARENT CAUSE WAS UNDETECTED BREAK IN THE ROOF STRATA.