A roof fall was found on the 1st 54 travelway at appox. 10:50 pm. The fall was 60'x18'x8'. Vent. and passage of men were not affected and no equip. was involved. The area had been mined in Aug. 2005 and supported with 9' cable bolts and 6' tension rebar roof bolts. 8' double-lock bolts were also installed in this area.The fall was caused by an undetected slip in the mine roof.