A ROOF FALL WAS DISCOVERED IN XCUTS FROM 5 LEFT THRU #5 & #6 ENTRIES INTO 6 RIGHT. THE ROOF WAS BOLTED WITH 6' TENSION REBAR BOLTS. IT MEASURED 19' W X 100' L X 8' H. LOCATION 1 LEFT OFF NW MA INS 1 XCUT INBY SS#3861. NO EQUIPMENT WAS INVOLVED. THE VENTILATION WAS NOT DISTURBED. NO INJURY OCCURRED. THE FALL WILL NOT BE CLEANED UP.