> During the final months of World War II, codenamed Cherry Blossoms at Night, the plan of Unit 731 was to use kamikaze pilots to infest San Diego, California, with the plague. The plan was scheduled to launch on 22 September 1945, but Japan surrendered five weeks earlier.
I had never heard of this either:
> During the final months of World War II, codenamed Cherry Blossoms at Night, the plan of Unit 731 was to use kamikaze pilots to infest San Diego, California, with the plague. The plan was scheduled to launch on 22 September 1945, but Japan surrendered five weeks earlier.
https://en.wikipedia.org/wiki/Unit_731#Biological_warfare