Abstract: A mechanical drop-away ceiling may include a frame and a panel. The frame may be configured to be suspended above a floor. The frame may include a movable element movable between a closed position and an open position. The panel may be selectively retained at the frame by the movable element in the closed position and may be free to drop away from the frame when the movable element is in the open position.

Abstract: In an embodiment, a method of accommodating a hazard mitigation system in a system including one or more fluid guides is described. The method includes forming a one-way valve in at least one of the one or more fluid guides. The one-way valve may be configured to substantially prevent the egress of fluid from the at least one of the one or more fluid guides through the one-way valve. The one-way valve may be further configured to allow ingress of a neutralizing agent supplied by a source outside the at least one of the one or more fluid guides through the one-way valve.