Abstract: An apparatus for sealably closing off or separating portions of a mine for safety or other reasons including an inflatable member having a size and shape which corresponds substantially to the cross-sectional size and shape of a mine passage, tunnel or the like to be closed off, a device for attaching the inflatable member to the ceiling of the mine passage, said inflatable member having an inflatable peripheral portion with a closure wall or web portion extending across the space defined by the inflatable portion, a source of compressed gas and means connecting said source to the inflatable portion of the member, said source including a valve with an actuator operable to open the valve so that gas from the gas source can pass into the inflatable member when the inflatable member is suspended from the ceiling of the mine passage, and a slide fastener located in the web portion of the member and movable between a first position in which an opening is formed in the web portion for passage therethrough and a sec