What is the primary objective of the initial size-up upon arrival at a structure fire?

• A. To locate the nearest hydrant and establish a water supply.
• B. Ensure all units are accounted for.
• C. To quickly assess occupancy type, location of the fire, building construction, hazards, life-safety needs, water supply, and to begin formulating the incident action plan.
• D. Establish a perimeter and stage apparatus outside.

Answer: (C)

The key idea being tested is that the first on-scene size-up should quickly gather critical information to shape the strategy and form the initial incident action plan. On arrival, you assess what type of occupancy you’re dealing with, exactly where the fire is and how it’s affecting the structure, the construction features and any risks they pose, potential hazards (gas, utilities, stairs, confined spaces), and the immediate life-safety needs (possible occupants, people needing rescue, or special considerations). At the same time you note whether a water supply is readily available or needs to be established, and you use all of that information to start laying out the initial action plan—deciding priorities (life safety, incident stabilization, property conservation), and guiding initial tactics such as interior vs. defensive stance, search and rescue needs, and ventilation decisions.

That’s why this option is the best fit: it captures the broad, integrative assessment that drives the early strategic choices. Locating a hydrant or establishing water supply is important, but that decision is part of the overall IAP rather than the sole focus of the initial size-up. Ensuring all units are accounted for and establishing a perimeter/staging are essential steps, but they stem from the information gathered in the size-up and the evolving plan, not the single primary objective of the arrival assessment.