If no attempts are made to extinguish a fire, during which stage will it continue to burn until fuel and/or oxygen is consumed?

The free burning stage is characterized by a significant and unrestricted release of heat and light. During this phase, the fire has enough fuel and oxygen to burn intensely and will continue to consume those resources as long as they are available. The fire reaches its peak intensity during this stage, rapidly consuming everything in its path until either the available fuel or oxygen is depleted.

In this context, the other stages do not sustain burning in the same way. The incipient stage involves the initial phase of combustion where the fire is just beginning and is often small. The smoldering stage refers to the low-temperature combustion that occurs without flames, typically when oxygen levels are low. The growth stage is the time during which a fire grows as it starts to become more developed, but it may not reach the intensity of the free burning stage yet. Thus, it is during the free burning stage that a fire can be sustained and will continue to burn until it exhausts its fuel and oxygen supply.