Near the end of World War II, Japan launched 9,000 hydrogen balloons into the atmosphere. These balloons weren't just for decoration though; each was carrying deadly anti-personnel shells and firebombs. The Japanese military hoped that the bombs would be steered by the Pacific trade winds to the United States, causing massive amounts of destruction in urban areas and triggering wildfires. The vast majority fell into the sea, while almost all of the balloons that did reach the US either caused no damage, or failed to detonate. Despite this, one of the balloons was responsible for the only civilian deaths on US soil during World War II, after a group of six children discovered a landed balloon and were killed when it was somehow triggered.
