Which is the second stage of a building fire's growth and development?

• A. Fully Developed
• B. Growth
• C. Incipient
• D. Decay

Answer: (B)

The second stage being tested is the growth stage, where the fire moves from its initial ignition into rapid spread and intensification. In this phase, flames begin to extend beyond the origin, more fuels and compartments become involved, and the heat release rate climbs quickly. You’ll see bigger flames, heavier, darker smoke, and much higher temperatures as the fire gains momentum and ventilation—open doors or windows can feed the fire and drive it to other areas of the structure. This stage sits between the early, localized incipient phase and the fully developed phase, where nearly everything in the building is involved, and before the decay phase, when fuels are exhausted or oxygen levels drop. Recognizing the growth stage helps explain why conditions can deteriorate fast and why tactics must adapt to the fire’s rapidly changing reach and intensity.