AN UNINTENTIONAL ROOF FALL OCCURRED AT 4 AND 80 ENTRY #1 IN THE 6TH NORTH INTAKE THE FALL DID NOT IMPEDE TRAVEL OR IMPAIR VENTILATION. THE FALL MEASURED 30' LONG 19' WIDE AND 3' THICK. THE FAL L DID NOT DAMAGE ANY EQUIPMENT. THE TOP WAS SUPPORTED BY 4' FULLY GROUTED ROOF BOLTS. THE 3 WAY INTERSECTION WAS DEVELOPED 12-2000.