Read about history and pick one out.

https://en.wikipedia.org/wiki/August_6

1945 – World War II: Hiroshima, Japan is devastated when the atomic bomb "Little Boy" is dropped by the United States B-29 Enola Gay. Around 70,000 people are killed instantly, and some tens of thousands die in subsequent years from burns and radiation poisoning.

1986 – A low-pressure system that redeveloped off the New South Wales coast dumps a record 328 millimeters (13 inches) of rain in a day on Sydney, New South Wales, Australia.

2010 – Flash floods across a large part of Jammu and Kashmir, India, damages 71 towns and kills at least 255 people.