Six people; one adult, Elsie Mitchell, wife of a local minister, and five children, on a picnic on Gearhart Mountain, in Oregon, were killed, on May 5, 1945, after they discovered a Japanese "Fu-Go" balloon bomb that exploded. These were the only known fatalities caused by enemy action in the continental U.S. during World War II. The bombs were designed to start forest fires.
The Japanese launched roughly 9,000 balloon bombs on the jet stream between late 1944 and April 1945; approximately 300 were found or observed in North America. The U.S. government initially censored news of the bombs to prevent panic, only warning the public after this fatal incident. A monument to the victims was erected and now stands at the site of the tragedy.