Which stage of fire development is characterized by a decrease in the supply of fuel or oxygen?

The decay stage of fire development is characterized by a decrease in the supply of fuel or oxygen. During this stage, the fire has consumed the available combustible materials in the area and is beginning to burn out. As the fire uses up the fuel and oxygen necessary for combustion, its intensity dwindles. The temperature drops, and the flames diminish in size as the fire transitions towards extinguishment. Furthermore, ventilation conditions might also change during this stage, leading to further reductions in oxygen concentration, which contributes to the fire's decline.

Understanding the decay stage is crucial for fire fighters, as it enables them to assess conditions accurately and develop appropriate strategies for extinguishing and preventing reignition.