after a two-month summer drought, combined with very high temperatures, several small fires started in the pine forests of pine county, minnesota. the fires' spread apparently was due to the then-common method of lumber harvesting, wherein trees were stripped of their branches in place; these branches littered the ground with flammable debris. also contributing was a temperature inversion that trapped the gases from the fires. the scattered blazes united into a firestorm. the temperature rose to at least . barrels of nails melted into one mass, and in the yards of the eastern minnesota railroad, the wheels of the cars fused with the rails. some residents escaped by climbing into wells, ponds, or the grindstone river. others clambered aboard two crowded trains that pulled out of the threatened town minutes ahead of the fire.