A ROOF FALL OCCURRED ON THE #1 PORTAL #1 MANTRIP TRACK AT 5 AND 70 FEET. FALL WAS 32 FT LONG, 19 FT WIDE AND 7 FT HIGH. AREA HAD BEEN ROOF BOLTED AND PIN TIMBERED. FALL OCCURRED DUE TO DETERI ORATION OF IMMEDIATE ROOF. THE FALL BLOCKED PASSAGE OF MATERIALS ON THE HAULAGE TRUCK.