DON'T BECOME A VICTIM YOURSELF
There will be too many victims already if an IED or CBR incident occurs.
DON'T ASSUME ANYTHING
Given that this is a terrorist event, booby traps, secondary devices and perpetrators may also be present.
DON'T TEST
Taste, eat, smell, and touch nothing. Any one of these actions may make you a casualty.
DON'T RUSH IN
Always assess the situation before doing anything. Avoid contamination. People and equipment that do not get contaminated do not have to be decontaminated. This minimizes risk, saves time and saves resources. Always minimize exposure. Move away from the hazard and relocate upwind. Establish an outer perimeter early in the incident. Control crowds, and do not let people pass by or through the affected area.