It was not at first apparent to even trained observers visiting the two
Japanese cities which of the two bombs had been the most effective.
In some respects, Hiroshima looked worse than Nagasaki. The fire
damage in Hiroshima was much more complete; the center of the city was
hit and everything but the reinforced concrete buildings had virtually
disappeared. A desert of clear-swept, charred remains, with only a few
strong building frames left standing was a terrifying sight.
At Nagasaki there were no buildings just underneath the center of
explosion. The damage to the Mitsubishi Arms Works and the Torpedo
Works was spectacular, but not overwhelming. There was something left
to see, and the main contours of some of the buildings were still
normal.
An observer could stand in the center of Hiroshima and get a view of
the most of the city; the hills prevented a similar overall view in
Nagasaki. Hiroshima impressed itself on one's mind as a vast expanse
of desolation; but nothing as vivid was left in one's memory of
Nagasaki.
When the observers began to note details, however, striking differences
appeared. Trees were down in both cities, but the large trees which
fell in Hiroshima were uprooted, while those in Nagasaki were actually
snapped off. A few reinforced concrete buildings were smashed at the
center in Hiroshima, but in Nagasaki equally heavy damage could be
found 2,300 feet from X. In the study of objects which gave definite
clues to the blast pressure, such as squashed tin cans, dished metal
plates, bent or snapped poles and like, it was soon evident that the
Nagasaki bomb had been much more effective than the Hiroshima bomb. In
the description of damage which follows, it will be noted that the
radius for the amount of damage was greater in Nagasaki than Hiroshima.