An unplanned roof fall occurred in the #2 entry @spad #3569, approx.4,000'from active face.Roof fall measured 80' long X 20' wide X 7' thick. Fall occurred in the return airway. Airway was not affected and will not be rehabilitated. State and Federal agencies notified immediately. This area was developed 9/15/09, area had been supported by 60"" Torque Tension bolts.