mortality at increasing distances from X:

TABLE C
Per-Cent Mortality at Various Distances

Distance from X, Per-cent Mortality
in feet
0 - 1000 93.0%
1000 - 2000 92.0
2000 - 3000 86.0
3000 - 4000 69.0
4000 - 5000 49.0
5000 - 6000 31.5
6000 - 7000 12.5
7000 - 8000 1.3
8000 - 9000 0.5
9000 - 10,000 0.0

It seems almost certain from the various reports that the greatest total
number of deaths were those occurring immediately after the bombing. The
causes of many of the deaths can only be surmised, and of course many
persons near the center of explosion suffered fatal injuries from more than
one of the bomb effects. The proper order of importance for possible
causes of death is: burns, mechanical injury, and gamma radiation. Early
estimates by the Japanese are shown in D below:

TABLE D
Cause of Immediate Deaths

City Cause of Death Per-cent of Total