Define Threatened Non Defensible

Define Threatened Non Defensible

• A. Safety Zones and TRA's present; full defense is feasible.
• B. Safety Zones not present; structure is safe.
• C. No Safety Zone or TRA's present. Structure has challenges that do not allow firefighters to commit to stay and protect the structure.
• D. Defensible space exists; risk is low.

Answer: (C)

This question tests how you judge whether a structure can be defended in a wildfire. The deciding factor is the availability of a safe operating space for firefighters: a Safety Zone around the structure and a Temporary Refuge Area (TRA) where crews can shelter if conditions intensify. If neither a Safety Zone nor a TRA is present, there’s no reliable place for firefighters to anchor their defense or retreat safely, so staying and protecting the structure isn’t feasible. In that situation, the structure is considered Threatened Non Defensible because protection cannot be conducted safely under the current conditions. The other scenarios would imply some form of defensible setup or safety margin, which would not fit this designation.

This question tests how you judge whether a structure can be defended in a wildfire. The deciding factor is the availability of a safe operating space for firefighters: a Safety Zone around the structure and a Temporary Refuge Area (TRA) where crews can shelter if conditions intensify. If neither a Safety Zone nor a TRA is present, there’s no reliable place for firefighters to anchor their defense or retreat safely, so staying and protecting the structure isn’t feasible. In that situation, the structure is considered Threatened Non Defensible because protection cannot be conducted safely under the current conditions. The other scenarios would imply some form of defensible setup or safety margin, which would not fit this designation.