If you look at a map of Japan, you will see that there is lots of sea around it. Well, around August-November time, the sea is at it's warmest. If a lightning bolt (or something with a similar amount...
kamikaze meaning divine wind
If you are meaning because of the nuclear bombs, 90,000-166,000 people in Hiroshima and 60,000-80,000 in Nagasaki.
There were 710 direct deaths from Typhoon Ketsana.
an earthquake kills about 1000 people