Hiroshima

Hiroshima was a city in Japan that was destroyed by a nuclear bomb towards the end of the Second World War.

On the eve of the September 11 attacks, Gary Seven reflected that he would not stop the events from occuring, just as he would not stop the the bombing or Hiroshima or the bombing of Pearl Harbor. (SS TOS (Assignment: One))

While at Starfleet Academy, Christopher Pike studied Hiroshima. 

Heihachiro Nogura had an ancestor who was killed by the blast at Hiroshima. 

The USS Hiroshima was named for the city.