However, the firestorms created by the bombing of German cities should interest us as firefighters from the aspect of fire protection and operational fire defense. Numerous block fires and larger great fires extended rapidly, merging into one great mass of fire blanketing a wide area, whereas conflagrations typically begin from one point and grow in size. Firefighting was defensive in nature and only possible at the perimeter of the block fires and great fires, here they could stop the spread but not extinguish fires in individual structures.