I learned years ago that in World War II the Japanese Empire had attempted to bomb the American west coast with balloons intended to cause forest fires. I even knew that these devices had actually killed some Americans.
What I did not know was that these bombs also hit Canada and landed as far inland as Manitoba.
Read all about it here, 74 years after the incendiary campaign:
http://www.amusingplanet.com/2018/05/the-japanese-balloon-bombs-of-world-war.html