AN UNINTENTIONAL ROOF FALL OCCURRED IN THE 4 WAY INTERSECTION OF ENTRY 2 ON THE 002 MMU @ 1+ 100. THE FALL WAS 50' LONG, 18' WIDE AND7' HIGH (THICK. DID NOT IMPAIR VENTILATION OR IMPEDE TRAVEL . THE AREA WAS DEVELOPED 12-26-00 & SUPPORTED WITH 6' FULLY GROUTED ROOF BOLTS & ALSO WAS CRIBBED OFF WITH SEVERAL CRIBS.