A breathable air safety system and method having at least one fill site is disclosed. In one aspect, a method of safety of a tunnel structure is disclosed. A prescribed pressure of an emergency support system is ensured to be within a threshold range of the prescribed pressure by including a valve of the emergency support system to prevent leakage of breathable air from the emergency support system. The prescribed pressure of the emergency support system is designated based on an authority agency that specifies a pressure rating of the breathable air apparatus. An air extraction process is expedited from the emergency support system by including a RIC (rapid interventions company/crew)/UAC (universal air connection) fitting to a fill panel to fill a breathable air apparatus.