Abstract: An active oxygen management, fire encirclement, and operational verification system. The system includes multiple doors and enclosing interior spaces, a programmable door controller, and at least one sensor associated with each of the doors. The sensors monitor predetermined conditions associated with the associated door. Each door controller is interconnected with each other door controller and contains instructions for communicating messages and commands to other specific door controllers if one or more of the predetermined conditions is determined to be an abnormal condition. If the abnormal condition is sensed by a sensor associated with one door, the programmable door controller associated with that door executes a predetermined set of instructions issuing a command to the programmable door controller associated with at least a second door. This command from the first door controller causes the second programmable door controller to execute a predetermined instruction set affecting the second door.