Which situation would most likely require a first responder's intervention?

A hazardous substance spill would most likely require a first responder's intervention due to the immediate risks associated with exposure to hazardous materials. First responders are trained to manage situations involving hazardous substances, including assessing the situation, ensuring public safety, and taking necessary actions to contain or mitigate the spill.

In contrast, a public health advisory serves as a warning or information source to the community about potential health risks but does not typically involve active intervention from first responders. A construction project may not inherently require first responders unless specific hazards arise that endanger safety. Similarly, an emergency evacuation plan outlines procedures for safely evacuating a location but does not involve first responders unless there is a current threat necessitating immediate action. Hence, the active nature of a hazardous substance spill highlights the need for trained intervention to protect health and safety.