An ordinary fire does not have enough energy to crack the molecular bond into combustible components. water poured on a fire inhibits combustion in a few different ways.if the water completely covers the fire, it displaces oxygen, preventing combustion.if the water is applied in such a way as to allow it to flash to steam, the process draws heat from the combustion process, which can cool it below the point of combustion.the cold water itself cools the process, which can cool it below the point of fire suppression activities, the water can also carry additives which inhibit combustion in various ways. if you do crack the molecular bond, and burn the resulting hydrogen and oxygen, the combustion by-product will be water.
The molecular strength of water is so strong that it cant be broken down by fire even in the process of latent heat.