What should be done immediately after securing a water supply at a structure fire?

Immediately after securing a water supply at a structure fire, the next critical step is to deploy hose lines. This action is essential because having a reliable water source is only part of the equation; effectively utilizing that water to combat the fire is the priority. Deploying hose lines allows firefighters to direct water to extinguish flames, cool hazardous materials, and protect exposures from catching fire.

While conducting a roll call, performing a hazard assessment, and calling for backup are important tasks within the overall incident management process, they do not directly address the immediate need to control and extinguish the fire. The deployment of hose lines ensures that firefighting efforts can begin right away, which is crucial in minimizing damage and ensuring the safety of both firefighters and civilians. This immediate action reflects the urgency and primary objective at a fire scene: controlling and extinguishing the fire as quickly and effectively as possible.