Injuries to persons resulting from the atomic explosions were of the
following types:

A. Burns, from
1. Flash radiation of heat
2. Fires started by the explosions.
B. Mechanical injuries from collapse of buildings, flying debris, etc.
C. Direct effects of the high blast pressure, i.e., straight
compression.
D. Radiation injuries, from the instantaneous emission of gamma rays and
neutrons.

It is impossible to assign exact percentages of casualties to each of the
types of injury, because so many victims were injured by more than one
effect of the explosions. However, it is certain that the greater part of
the casualties resulted from burns and mechanical injures. Col. Warren,
one of America's foremost radioligists, stated it is probable that 7 per
cent or less of the deaths resulted primarily from radiation disease.

The greatest single factor influencing the occurrence of casualties was the
distance of the person concerned from the center of explosion.

Estimates based on the study of a selected group of 900 patients indicated
that total casualties occurred as far out as 14,000 feet at Nagasaki and
12,000 feet at Hiroshima.

Burns were suffered at a considerable greater distance from X than any
other type of injury, and mechanical injuries farther out than radiation
effects.