The invention relates to compositions that prevent expansion of a fire, suppress existing fire, as well as methods of preparing and using such compositions. The composition is comprised of water, pseudo-plastic high yield suspending agent and starch. Compositions may contain additional functional agents, such as rheological, wetting, foaming, coloring, chelating, antimicrobial and stabilizing agents. In the description of the present invention, all composition modifications are referred to as compositions. The composition, an augmentation of water, exhibits the characteristics of a sag resistant aqueous gel in the tank, but has shear thinning capacity, allowing the composition to be pumped or sprayed as easily as water. At the point of impact, when the sprayed composition is again at rest, it instantly reverts to a sag resistant aqueous gel. The composition also forms an intumescent, surface char layer upon contacting a fire. Foaming of the augmented composition on impact can be incorporated, which is advantageous for fighting petroleum fires.