Our Gemara quotes a baraita that compares and contrasts damage done by a bor and by esh (fire). According to the baraita, there is an element of severity to each of these two avot nezikin. On the one hand, the very creation of a bor in a public place is meant to injure or damage; on the other hand, by its very nature esh travels and does damage when it moves, furthermore it destroys not only things that ordinarily burn, but also things that do not ordinarily burn.
Although fire can only burn flammable objects and not stones or dirt, nevertheless fire does damage them, as well. After a fire, various organic elements that add nutrients to the soil – e.g. straw, excrement and rotting vegetation – are destroyed. In addition to this, moisture is drawn out of the ground, leading it to break up, which makes it difficult to plow and farm.
This is also true regarding rocks. In the land of Israel, most rocks are made up of different types of chalk, and a large fire can crack them and break them apart. Even smaller fires may have an effect on the chemical composition of the rock – at least its outer surface – leading it to become brittle, so that it may disintegrate in rain.
Aside from these types of damages, the heat from fire can also potentially affect other non-flammable objects like metal objects, pottery and stoneware as well as other things.