A door for use at a doorway through a wall, the doorway having a height extending in a vertical direction between a floor and an upper edge of the doorway, the doorway having a width extending in a horizontal direction between a first lateral edge and a second lateral edge of the doorway, the door comprising: an overhead track proximate the upper edge of the doorway; a panel assembly suspended from the overhead track such that the overhead track carries at least most of the panel assembly's weight, the overhead track guiding the panel assembly in translation along a predetermined normal path between an open position and a closed position relative to the doorway, the panel assembly blocking more of the doorway when the panel assembly is in the closed position than when the panel assembly is in the open position, the panel assembly having selectively a normal configuration and a dislodged configuration, the panel assembly in its entirety lying within the predetermined normal path when the panel assembly is in the normal configuration, at least a portion of the panel assembly being displaced beyond the predetermined normal path when the panel assembly is in the dislodged configuration; a lower track attached to at least one of the floor and the wall, the lower track being at a lower elevation than that of the overhead track, the lower track being interposed between the wall and the panel assembly when the panel assembly is in the open position, the lower track defining a roller passageway; and a spring loaded roller mounted to the panel assembly, the spring loaded roller having selectively a guiding configuration and a release configuration, the spring loaded roller being in the guiding configuration and extending into the roller passageway when the panel assembly is in the normal configuration and halfway between the open position and the closed position, the spring loaded roller being in the release configuration and outside the roller passageway when the panel assembly is in the dislodged configuration and halfway between the open position and the closed position. an overhead track proximate the upper edge of the doorway; a panel assembly suspended from the overhead track such that the overhead track carries at least most of the panel assembly's weight, the overhead track guiding the panel assembly in translation along a predetermined normal path between an open position and a closed position relative to the doorway, the panel assembly blocking more of the doorway when the panel assembly is in the closed position than when the panel assembly is in the open position, the panel assembly having selectively a normal configuration and a dislodged configuration, the panel assembly in its entirety lying within the predetermined normal path when the panel assembly is in the normal configuration, at least a portion of the panel assembly being displaced beyond the predetermined normal path when the panel assembly is in the dislodged configuration; a lower track attached to at least one of the floor and the wall, the lower track being at a lower elevation than that of the overhead track, the lower track being interposed between the wall and the panel assembly when the panel assembly is in the open position, the lower track defining a roller passageway; and a spring loaded roller mounted to the panel assembly, the spring loaded roller having selectively a guiding configuration and a release configuration, the spring loaded roller being in the guiding configuration and extending into the roller passageway when the panel assembly is in the normal configuration and halfway between the open position and the closed position, the spring loaded roller being in the release configuration and outside the roller passageway when the panel assembly is in the dislodged configuration and halfway between the open position and the closed position.