safes, chimney stacks, and pieces of twisted sheet metal. The fire damage
resulted more from the properties of the cities themselves than from those
of the bombs.

The conflagration in Hiroshima caused high winds to spring up as air was
drawn in toward the center of the burning area, creating a "fire storm".
The wind velocity in the city had been less than 5 miles per hour before
the bombing, but the fire-wind attained a velocity of 30-40 miles per hour.
These great winds restricted the perimeter of the fire but greatly added to
the damage of the conflagration within the perimeter and caused the deaths
of many persons who might otherwise have escaped. In Nagasaki, very severe
damage was caused by fires, but no extensive "fire storm" engulfed the
city. In both cities, some of the fires close to X were no doubt started
by the ignition of highly combustible material such as paper, straw, and
dry cloth, upon the instantaneous radiation of heat from the nuclear
explosion. The presence of large amounts of unburnt combustible materials
near X, however, indicated that even though the heat of the blast was very
intense, its duration was insufficient to raise the temperature of many
materials to the kindling point except in cases where conditions were
ideal. The majority of the fires were of secondary origin starting from
the usual electrical short-circuits, broken gas lines, overturned stoves,
open fires, charcoal braziers, lamps, etc., following collapse or serious
damage from the direct blast.

Fire fighting and rescue units were stripped of men and equipment. Almost
30 hours elapsed before any rescue parties were observable. In Hiroshima
only a handful of fire engines were available for fighting the ensuing
fires, and none of these were of first class type. In any case, however,
it is not likely that any fire fighting equipment or personnel or
organization could have effected any significant reduction in the amount of