As a result of the concentric enemy attacks and the heavy concentration of incendiaries a huge number of fires developed in such areas in a very short time. It should be noted in particular that there were not only roof fires but, as a result of phosphor bombs and liquid [petrol and rubber] bombs, in many areas large blocks of flats were suddenly set alight from the bottom floor. The fires could develop with incredible speed since roofs had been torn off, walls had caved in, windows and doors had been torn out of their frames or smashed by concentrated attacks with high-explosive bombs and mines and on these the fires could feed without any hindrance. For these reasons, the intermediate stage of the fire's development, which in the case of previous raids it was possible to combat and which produced some of the biggest successes of the Hamburg civil defense forces, did not occur. For in many places extensive fires developed in a very short time. And because of the laws of physics, which have been outlined above, a firestorm developed in every one of these districts where there was an extensive fire. The suction effect of the firestorm in the larger or largest of these extensive fire areas had the effect of pulling in the already superheated air of the smaller fire areas. So the cores of the most ferocious fire areas sucked the fires from the smaller fire areas towards them. As a result of this phenomenon, fires in the smaller fire areas were pumped up as if by bellows, since the central suction effect of the largest and strongest extensive fires had the effect of pulling in the surrounding masses of fresh air. In consequence, all the fires grew into a single huge conflagration.
In order to form an impression of this massive firestorm which was created from countless smaller fires, one must bear in mind that, for example, the area affected by the major raids on 28 July was some 5.5km long and 4km wide, i.e. 22 sq. km in extent.
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The speed with which the fires and firestorm developed negated all plans and every attempt by the population to fight them. Houses which in the previous raids had been able to be saved by the brave actions of the civil defense and other forces, fell victim to the flames. In many cases escape routes were cut off before the need to escape became apparent.
After the alarm was sounded, the civil defense forces waited in their shelter, the firefighters in the extended civil defense and factory defense units were at their posts awaiting the start and progress of the raid. Sticks of high-explosive bombs shattered the houses down to their foundations. Already a short time after the first explosive bombs had fallen, a huge number of fires had started as a result of a massive amount of incendiaries mixed with high-explosive bombs. People who now wanted to leave their shelters in order to see what was happening or to fight the fire were met by a sea of flames. Everything around them was on fire. There was no water and, in view of the huge number of fires and their extent, any attempt to put out the fire was useless from the start.
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