Starting around fall of 1944, US military planes flew over Japan's air
space to carry out air raids. When a fighter plane approached an area,
an air-raid siren sounded and people ran to air-raid shelters for cover.
In 1945, the U.S. military attacked the major Japanese cities from
the air, one after another. The air strikes did severe damage. Though
sirens sounded in Hiroshima as well , air strikes were rare.