Which of the following is NOT one of the three key elements of a fire?

Fire requires three key elements to exist, commonly referred to as the "fire triangle." These elements are oxygen, heat, and fuel. Oxygen helps sustain combustion, heat is needed to ignite the fuel, and fuel is the substance that burns.

Water, while often used to extinguish fire, is not a necessary element for the fire to occur. It does not contribute to the combustion process and is therefore not part of the fire triangle. Understanding these fundamental elements is crucial for both fire prevention and firefighting strategies.