A fire-extinguishing composition has a water-thickening agent and a foaming agent. The fire-extinguishing composition contains less than 10 vol % water. The ratio of water-thickening agent to foaming agent is from 99:1 to 1:99 volume ratio. The composition is in the form of a powder or flake. A method of extinguishing a fire is by applying a mixture of a fire-extinguishing composition and water to a fire, the fire-extinguishing composition having a water-thickening agent and a foaming agent.