Final answer:
A firefighter's primary concern in determining the collapse zone for a type 2 structure fire is to ensure the safety perimeter accounts for potential outward collapse of walls, which could extend one and a half times the building's height.
Step-by-step explanation:
When a firefighter arrives at a scene where a type 2 structure is on fire, the primary concern in determining the collapse zone is ensuring that the area encompasses a perimeter large enough to account for the potential collapse of outer walls.
In the event of a structural failure, these walls could fall outward up to one and a half times the height of the building, posing a significant threat to the safety of both firefighters and bystanders. A type 2 structure, often composed of tilt slab or reinforced masonry, presents a risk of sudden and unpredictable collapse, especially under intense fire conditions. Establishing an adequately sized collapse zone is a critical part of fire and rescue efforts to protect life and property.