AN UNINTENTIONAL ROOF FALL WAS DISCOVERED WHILE TRAVELING THE NEUTRAL ENTRY AT SURVEY STATION #547 #3 ENTRY. THE FALL MEASURED 80' LONG X 20' WIDE X 42"" THICK. ALL ENTRANCES HAVE BEEN BREAKE RED OFF. PASSAGE OF PERSONS AND VENTILATION WAS NOT AFFECTED. AREA WILL NOT BE REHABILITATED.