Did you know that in WW2 the Japanese launched 9000 balloons bombs towards North America, of which at least 300 successfully landed in the US. Fascinating.
They were meant to cause waves of terror and the US Office of Censorship forbid media from discussing the balloons. In actuality, there were six casualties from one tragic incident.
The other notable explosion was a balloon taking out power lines to the Manhattan Project nuclear reactor, causing a short circuit but backup power saved the day.