What is the signal for an evacuation order during a structural collapse incident?

In the context of an evacuation order during a structural collapse incident, the signal of one long blast, lasting approximately 10 seconds, is widely recognized in emergency response protocols. This specific signal is distinct and designed to be easily understood amidst the chaos that can accompany a structural collapse, ensuring that individuals on the scene clearly comprehend the urgency of the situation.

The use of a long continuous blast is intended to attract immediate attention and convey a serious message. It allows for a clear distinction from other signals that might be used in different contexts, preventing any potential confusion during a critical evacuation process.

Other options may not provide the same level of clarity or urgency required in a rescue context, where every second counts in ensuring the safety of personnel and civilians. The standardized use of a long blast helps ensure consistency in communication among responding units and personnel on the scene.