MINE EXPERIENCED A NON-INJURY, UNINTENTIONAL ROOF FALL ON OLD SUBMAINS, OUT BY THE ACTIVE SECTION FOR MMU-012-0. FALL WAS APPROX 100 FT LONG, 20 FT WIDE, AND 5-7 FT THICK. LAMINATED SLATE AND SANDSTONE GAVE WAY. THE AREA WAS INITIALLY SUPPORTED WITH 60 INCH FULLY GROUTED RODS. NO DAMAGE TO PROPERTY. ROOF FALL WAS DISCOVERED DURING A WEEKLY EXAMINATION.