A ROOF FALL WAS FOUND THAT BLOCKED THE TRAVELWAY IN THE AIR COURSE. THE FALL WAS LOCATED AT 258 X CUT, 274 & 80 FEET INT HE 65 ENTRY OF MAIN NORTH. THE FULL WAS 28 FT LONG BY 16 1/2 FT WIDE X 7 FT HIGH. FALL OCCURRED DUE TO WATER DETERIONATING THE IMMEDIATE ROOF AROUND THE ROOF BOLTS. THE ROOF BOLTS USED WERE 8 FT LONG, POINT ANCHOR BOLTS, 34 INCH DIAMETER, WITH 2 FT OF RESIN. HEAD