The phase of fire characterized by diminishing fire is:

• A. Ignition
• B. Decay
• C. Fully developed
• D. Growth

Answer: (B)

Fire behavior moves through stages. After ignition and the early growth, the fire enters a stage where fuel is largely exhausted and the heat release begins to fall. This is the decay stage. In decay, flames shrink, temperatures drop, and smoke may continue to flow as remaining embers burn out. Recognizing decay helps anticipate waning energy at the scene, though hazards remain, such as the potential for rekindling if fresh air reaches unburned embers. The other stages are ignition, when the fire just starts and heat release is increasing; growth, when the fire spreads and intensifies; and fully developed, when the fire has maximum intensity and consumes the available fuels.