Which of the following is not one of the three rules for dealing with an explosive device on an active shooter scene?

Maintaining communication among all units is indeed vital for effective incident management, particularly during chaotic situations such as an active shooter event. However, it is not classified as one of the three primary rules for dealing specifically with an explosive device on the scene.

The focus when encountering a potential explosive device involves the immediate actions that prioritize safety and risk mitigation. Creating distance with angles and air-gaps helps reduce the risk of injury from a potential explosion by positioning individuals at a safe distance. Establishing a secure perimeter prevents unauthorized or unnecessary personnel from entering the danger zone, safeguarding both individuals on-site and first responders who may need to operate in the vicinity. Evacuating all non-essential personnel is crucial in minimizing the number of people exposed to potential harm.

In summary, while communication is critical in emergency response settings, it does not directly relate to the specific strategies for managing explosive devices. The three rules focus on physical safety measures that are more immediately pertinent in an active shooter scenario involving explosives.