A ROOF FALL OCCURRED IN THE #3 ENTRY #8 BK OF 21 BUTT SECTION. THE ALL WAS APPROX. 55 FT LONG X 9 FT HIGH AND 16 FT WIDE. AREA WAS SUPPORTED TO PLAN WITH ADDITIONAL MONSTER MATS, 6 FT HY TEK B OLTS AND 4 FT RIB SUPPORT BOLTS. NO DAMAGE AND NO INJURIES INVOLVED.