Were Japanese balloon bombs dropped on the US during WWII?

The Japanese balloon bombing offensive on US soil was one closely guarded secret for the latter part of World War II. It was one of a few instances Japanese attacks on US soil and the bombing of Pearl Harbor in 1941.

We received questions from our readers about these mysterious balloon bombs and found numerous claims about them online:

The Japanese use of balloon bombs to attack US targets is indeed one documented Part of World War II history, although not as well known as other incidents such as the attack on Pearl Harbor. This lack of knowledge was partly intentional. The US Censorship Board had asked journalists not to cover the balloon bombing offensive, lest such news reach the Japanese, and also, allegedly, Avoid panic among civilians. Discouraged by what they believed to be failed attacks, the Japanese stopped launching balloons in April 1945.

But how did they start? According to a 1973 account in the Smithsonian Annals of Flight by Robert C. Mikesh entitled “Japan’s World War II balloon bombing raids on North America,” the attacks could have been a reaction to the American attack by the “Doolittle Raiders” on Tokyo in 1942 Doolittle Raid, which sent a number of B-25 Mitchell bomber planes across Japanese skies, was intended to “create confusion and hamper production” in Japan. In response, the Japanese spent the next two years building balloons to be launched over the Americas with incendiary and anti-personnel bombs.

At November 3, 1944the first of more than 9,000 bomb-carrying balloons was released. An estimated 1,000 are said to have reached the United States only about 300 were reported as landing on US soil, according to the Washington Post.

Mikesh’s report described the first discovery of such a balloon as a “mystery” rather than an immediate concern:

This sighting occurred on November 4, 1944, when a Navy patrol boat spotted what appeared to be a large piece of shredded cloth floating in the sea 66 miles southwest of San Pedro, California. The unidentified debris was towed aboard and soon identified as a rubberized silk balloon with heavy landing gear attached. Ironically, this balloon from the first group launched on November 3 (Japan date) was only two days earlier – two days because of the International Date Line.

The apparatus, still attached to the balloon’s landing gear, consisted of a small radio transmitter. The equipment bore Japanese markings, hinting that something new and mysterious had been introduced in these final months of the war.

The incident was reported through military channels, but raised little concern until a second fragment was recovered from the ocean two weeks later. Within the next four weeks, balloons were found in Wyoming and Montana. This clear evidence of a new and unexpected balloon-borne weapon was a cause for growing concern and the support of all government agencies at the national, state and local levels was immediately enlisted.

Rangers – state and national – were instructed to report every balloon landing and every recovery of parts of balloons or their landing gear.

Large balloons were menacing reported in numerous cases by farmers, ranchers, lumberjacks and others in various parts of the United States from 1944 to about May 1945.

These balloon bombs were also the only means by which US civilians were killed by enemy attacks on the US mainland. After the Japanese halted their balloon launches in May 1945, a group of people unknowingly found themselves at the mercy of one of the remaining balloons. The Smithsonian details the death of a woman and five children in Oregon:

Elsye Mitchell almost didn’t go to the picnic on this sunny day in Bly, Oregon. She had baked a chocolate cake the night before in anticipation of her outing, her sister later recalled, but the 26-year-old was pregnant with their first child and was unwell. On the morning of May 5, 1945, she decided she felt decent enough to join her husband, Rev. Archie Mitchell, and a group of Sunday school children from their close-knit community as they set out for nearby Gearhart Mountain in southern Oregon. Set against a scenic backdrop far from the war that raged in the Pacific, Mitchell and five other children would be the first – and only – civilians to die at the hands of enemy guns on the mainland United States during World War II.

While Archie was parking her car, Elsye and the kids came across a strange looking object in the woods and called back. The pastor later described this tragic moment to local newspapers: “I … hurriedly shouted a warning to them, but it was too late. Just then there was a big explosion. I ran up – and they all lay dead.” Immediately, his wife and unborn child were alongside Eddie Engen, 13, Jay Gifford, 13, Sherman Shoemaker, 11, Dick Patzke, 14, and Joan “Sis” Patzke (13) lost.

Although journalists were prevented from covering the balloon bombings, following the Oregon deaths, the Ministry of War issued a statement describing them so people finding debris would know not to touch them.

Mikesh told The Washington Post that while the bombs were technically successful, they had minimal effects, especially since they could not be controlled. They had also been launched in winter and not in the dry season where wildfires could have increased damage.

“They didn’t have that luxury,” Mikesh said. “They had to launch them if they could.”

The balloons were built largely by Japanese schoolchildren who assembled them from laminated layers of tissue paper made from mulberry tree fibers.

Mikesch written down in his account of the legacy of balloons:

Historians tend to downplay this use of mankind’s oldest aircraft in what appears to be a pathetic last-ditch effort to exact revenge on the United States. However, it was a significant development in military concept and predated today’s land-launched and submarine-launched ICBMs. Had this balloon weapon been further exploited through the use of germ or gas bombs, the results could have been disastrous for the American people.

There were actually only two balloons shot down by the US military over North America. In an attempt years later recognized as a mistake by the US Naval Institute, they actually mistook a planet for the balloon. They wrote on Facebook: “As the USS New York (BB-34) sailed towards Iwo Jima in 1945, the crew spotted a silver orb flying high overhead that appeared to follow the battleship for hours. Concerned that the shiny bullet might be a Japanese balloon gun, the captain ordered it shot down. After the guns failed to score a hit, a navigator realized they were attacking Venus.

How many of us are caught up in the news about this Chinese spy balloons over US soil in 2023, we should remember that this is not the first time giant balloons have been sent across the oceans to North American shores.