Sliding door with large opening

A door assembly comprising:

• a fixed track header constructed and arranged to be mounted in fixed relation with respect to an opening formed through a wall to which the door assembly is installed;
• a track;
• a fixed door panel constructed and arranged to be fixed relative to the track, and at least two sliding door panels constructed and arranged to be slidably movable on the track, wherein the at least two sliding door panels are constructed and arranged to be slidably movable on the track between (1) a closed position wherein the at least two sliding door panels are extended across the track, and (2) an open position wherein the at least two sliding door panels are constructed and arranged to be in a compact, overlapping relationship with each other and the fixed door panel;
• a drive mechanism constructed and arranged to drive the at least two sliding door panels between the closed position and the open position, wherein the drive mechanism is mounted on the fixed track header;
• a pivot mechanism constructed and arranged to enable pivotal movement of the track with the fixed door panel and the at least two sliding door panels mounted thereon, about a pivot axis from (1) a normal configuration wherein the track is positioned such that the door panels will cover the opening when in the closed position, to (2) a breakaway configuration wherein the track is pivoted away from the normal configuration;
• and
• a lock arrangement constructed and arranged to releasably lock the track with respect to the fixed track header to prevent pivotal movement of the track away from the normal configuration, the lock arrangement configured to enable the track to be unlocked with respect to the fixed track header and enable the track with fixed door panel and the at least two sliding door panels mounted thereon to be pivoted away from the normal configuration to the breakaway configuration.