During World War II, Japan attempted to attack the US mainland by floating hydrogen-filled balloons equipped with incendiary devices across the Pacific Ocean. In 1944 and 1945, the Japanese launched over 9,000 of the weapons, which were designed to kill, destroy property, and start fires. Although, at the request of the US government, fire balloon incidents were not reported by the press at the time, about 300 such bombs are known to have reached N America. Of these, how many caused casualties? Discuss
Source: The Free Dictionary