Colonel Jimmy Doolittle’s bombing raid on Tokyo and other cities on April 18, 1942, may have inflicted little material damage, but was a severe blow to Japanese pride. The attacks prompted the Japanese to seek a way to bring the war to the United States. It took two years before they found the right instrument: a new weapon, the balloon bomb. From November of 1944 to April of 1945, the Japanese launched over 9,000 balloons armed with explosives into the jet stream, for a flight of over 6,000 miles to the United States, which normally took about three days.

The balloons consisted of several layers of tissue paper made from the “kozo” bush, cemented together with glue made from potatoes. The seams of the paper had to be perfect; there could be no leaks in the balloon. When completed, the balloons received a coat of lacquer and were tested for leaks. A cloth mesh covered the balloon, to which workers attached shroud lines.

The Japanese inflated the balloons with highly flammable hydrogen gas. This meant extreme caution had to be taken in determining a launch site, since heavy winds during the filling process or balloon launch could create a disaster. Inflated, a balloon measured 33½ feet in diameter.

After detailed studies of the air currents, the Japanese determined that 35,000 feet was the best launch altitude in order to take advantage of the jet stream. Each balloon bomb had a ballast mechanism that released two sand bags when it went below a minimum altitude, about 30,000 feet. The balloon carried a total of thirty-two sandbags, and when all the bags were released the balloon was expected to be over the target and the bomb release mechanism dropped the bombs. The balloons carried a payload from 25 to 65 pounds of anti-personnel and incendiary bombs. With the bombs dropped, a self-destruction charge exploded, destroying any trace of the balloon.

The Japanese launched the balloons from the Sendai area of Honshu Island. An estimated 1,000 balloons made it to North America. The United States Government recorded 285 balloon occurrences, most in the Northwestern states, but balloons reached as far north as Canada, south to Mexico and east to Michigan.

The U. S. Government did their best to keep the balloons a secret. In January 1945, the Office of Censorship contacted news agencies to censor any reports of the balloon bombs in the name of national security. Government officials did not want the Japanese know the success or failure of the balloon bomb program, nor did they want to create a panic in the United States.

However, Government censorship of the balloon bomb attacks left U. S. residents unaware of the dangers of the bombs if they found them. This policy changed after the first deaths from a balloon bomb occurred. On May 5, 1945, near Bly, Oregon, Reverend Archie Mitchell of the Bly Christian & Missionary Alliance Church and his pregnant wife, along with five Sunday school children, went for a picnic. Reverend Mitchell pulled off the road by a creek so they could do little fishing and eat their picnic lunch. One of the children spotted something, and Mrs. Mitchell and the other children ran to see what it was. Suddenly there was an explosion, which left Mrs. Mitchell and the five children dead. They were the only recorded deaths on United States soil as a result of enemy military action during World War II.

The Japanese hoped the incendiary bombs would cause forest fires in the Northwestern United States. Once the threat from the balloon bombs was identified, the Army sent the all- African American 555^th Parachute Infantry Battalion to the West Coast to fight forest fires. The men fought a number of forest fires, but none occurred due to the balloon bombs.

The balloon bombs caused some U.S. officials to become concerned about the possible delivery of biological agents by balloon. Although the Japanese did experiment with using balloons in this fashion, no evidence exists that they ever actually employed any.

Defense against the balloon bomb was difficult. By 1945, fear of a Japanese invasion had diminished and the early warning air defense stations on the West Coast were at a low level of alert. Spotting a balloon flying at 30,000 feet and shooting it down was problematic. The paper balloon did not appear on radar; only the metal valve release assembly might possibly have been spotted.

One of the officially recorded sightings of a balloon bomb occurred on February 1, 1945, near Hayfork, California. Several residents spotted a balloon as it passed over the Trinity National Forest. The balloon became caught in a fir tree, attracting the attention of several local residents. It contained four incendiary bombs and one high explosive bomb. That evening the bombs exploded destroying the balloon. The remaining undercarriage came to rest on the ground. Forest rangers contacted Army officials, who requested that the local residents not discuss what they saw. Over several months the U. S. Army recovered several more Japanese balloons and studied them carefully. They even inflated and flew some balloons to determine how effectively radar systems could spot them.

The balloon bomb project did not create the planned forest fires or panic that the Japanese expected. The overall lack of control of the balloon bomb proved to be the downfall of the project. The government blackout on news about balloon bombs found in the United States probably also helped to bring the project to an end.

In May 1949, the United States paid $20,000 to the families of the victims of the balloon bomb explosion, with $5000 to the husband of Elise Mitchell and $3000 each to the parents of the children. From time to time a balloon bomb turns up here ant there, and it’s likely that some more will probably be found.

R. J. Musto has worked as an internal auditor in private industry for over twenty-three years. R. J. has always enjoyed history, and in his spare time writes for numerous magazines, with a particular specialty in the American Civil War. His articles have appeared in Arizona Highways, The Backwoodsman, Journal of the Everyday Sportsman, North & South, Patriots of the American Revolution, The Washington Times, Australian Railway History, and The Irish Roots. He resides in Pittston, Pennsylvania with his wife Mary Kay.