A unplanned roof fall occurred at #1 entry in the Parrell Mains 1 break inby spad # 789. 4000' from active face. Fall meas. 100' L. X 20' W. X 6-8' thick. No Eq. or injuries. Roof fall did not affect ventilation or passage of persons. The fall will not be rehab'd. Area supported with 48"" resin bolts. Federal and State Agencies were notified immead.