cept 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 damage caused by the tremendous conflagration.

A study of numerous aerial photographs made prior to the atomic
bombings indicates that between 10 June and 9 August 1945 the Japanese
constructed fire breaks in certain areas of the cities in order to
control large scale fires. In general these fire breaks were not
effective because fires were started at so many locations
simultaneously. They appear, however, to have helped prevent fires
from spreading farther east into the main business and residential
section of Nagasaki.

TOTAL CASUALTIES

There has been great difficulty in estimating the total casualties in
the Japanese cities as a result of the atomic bombing. The extensive
destruction of civil installations (hospitals, fire and police
department, and government agencies) the state of utter confusion
immediately following the explosion, as well as the uncertainty
regarding the actual population before the bombing, contribute to the
difficulty of making estimates of casualties. The Japanese periodic
censuses are not complete. Finally, the great fires that raged in each
city totally consumed many bodies.

The number of total casualties has been estimated at various times
since the bombings with wide discrepancies. The Manhattan Engineer
District's best available figures are:

TABLE A
Estimates of Casualties

Hiroshima Nagasaki
Pre-raid population 255,000 195,000
Dead 66,000 39,000
Injured 69,000 25,000
Total Casualties 135,000 64,000

The relation of total casualties to distance from X, the center of
damage and point directly under the air-burst explosion of the bomb, is
of great importance in eva