AN UNINTENTIONAL ROOF FALL WAS DISCOVERED IN THE LEFT RETURN AIR ENTRY APPROX. 500' OUTBY THE WORKING SECTION SPAD NO. 2169. FALL IS APPROX 20' L X 18' W AND UP TO 10' IN HEIGHT. AREA HAD BEED SUPPORTED WITH 42"" & 72"" ROOF BOLTS AND WOODEN CRIBS. FALL OCCURRED IN FAULT AREA AND FELL UP TO SMALL RIDER SEAM.