During World War II the Japanese built some nine thousand hydrogen-filled, paper balloons to carry small bombs to North America, hoping to set fires and inflict casualties. The first was launched November 3, 1944. The balloons rose to about 30,000 feet, where winds aloft transported them across the Pacific Ocean. On February 22, 1945, Kenneth Hamilton, living on a nearby ranch, observed a balloon floating eastward. It looked like "an orange ball with the sun shining on it. . . . As we were watching, it turned into a cloud of smoke and went to the ground." The balloons carried timing devices to release the bombs and then destroy the envelope. Alliance Army Air Field officials recovered a valve and pieces of shroud lines where the balloon came down. Parts of five balloon bombs were recovered in Nebraska from a total of 285 balloon bomb incidents reported across North America. Although the balloon bombs proved ineffective as military weapons, they caused six fatalities and a few minor fires in the United States. Only after the war was their story revealed.