A ROOF FALL OF APPROXIMATE DIMENSIONS 30' L BY 16' W BY 8' H OCCURRED IN THE INTAKE ENTRY OF THE NO. 2 SW MAINS AT SURVEY STATION 1759. THIS LOCATION IS APPROX 6000' OUT BY THE ACTIVE 003-M MU. NO INJURY OR DAMAGE TO EQUIPMENT OCCURRED. THE FALL IS NOT PLANNED TO BE CLEANED UP.