Were Japanese Balloon Bombs Released Over the US During WWII?

Pearl Harbor was not the only Japanese attack on American soil.

Published Feb 15, 2023

 (National Museum of the U.S. Navy/Wikimedia Commons)
Image Via National Museum of the U.S. Navy/Wikimedia Commons

The Japanese balloon bomb offensive on U.S. soil was a closely guarded secret for the latter part of World War II. It marked one of a handful of instances of Japanese attacks on U.S. soil in addition to the bombing of Pearl Harbor in 1941. 

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

The Japanese use of balloon bombs to attack targets in the U.S. is indeed a documented part of World War II history, though it is not as widely known as other incidents like the attack on Pearl Harbor. This lack of knowledge was partly by design. The U.S. Office of Censorship had asked journalists to not report on the balloon bomb offensive so that such news would not reach the Japanese, and also, reportedlyto avoid causing panic among civilians. Discouraged by what they thought were failed attacks, the Japanese stopped launching balloons by April 1945. 

But how did they begin? According to a 1973 report in the Smithsonian Annals of Flight by Robert C. Mikesh, titled, "Japan's World War II Balloon Bomb Attacks on North America," the attacks may have been a response to the American attack of the "Doolittle Raiders" against Tokyo in 1942. The Doolittle raid, which sent a number of B-25 Mitchell bomber aircraft over Japanese skies was intended to "cause confusion and impede production" in Japan. In response, the Japanese spent the next two years creating balloons to launch over the American continent, with incendiary and anti-personnel bombs attached to them. 

On Nov. 3, 1944, the first of more than 9,000 bomb-bearing balloons were released. An estimated 1,000 were believed to have reached the U.S. Only around 300 were reported as landing on U.S. soil, according to The Washington Post. 

Mikesh's report detailed the first discovery of such a balloon as more of a "mystery" than an immediate concern: 

This sighting was on 4 November 1944, when a navy patrol craft spotted what looked like a large fragment of tattered cloth floating on the sea, sixty-six miles southwest of San Pedro, California. The unidentified debris was hauled on board, and was soon determined to be a rubberized-silk balloon with a heavy undercarriage attached. Ironically, this balloon was from the first group launched on 3 November (Japan date), just two days earlier—two days because of the international dateline.

The apparatus, still connected to the undercarriage of the balloon, consisted of a small radio transmitter. The equipment bore Japanese markings and indicated that something new and mysterious had been introduced into these final months of the war.

The incident was reported through military channels, but it caused little concern until two weeks later when a second fragment was salvaged from the ocean. Within the next four weeks, balloons were found in Wyoming and Montana. This clear evidence of a new and unexpected balloon-borne weapon gave rise to increased concern, and the assistance of all government agencies national, state, and local—was immediately summoned.

Forest rangers—state and national—were ordered to report any balloon landings and any recoveries of portions of balloons or their undercarriages.

Menacing large balloons were reported in numerous instances by farmers, ranchers, loggers, and others in different parts of the U.S. from 1944 to around May 1945. 

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

Elsye Mitchell almost didn't go on the picnic that sunny day in Bly, Oregon. She had baked a chocolate cake the night before in anticipation of their outing, her sister would later recall, but the 26-year-old was pregnant with her first child and had been feeling 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 tight-knit community as they set out for nearby Gearhart Mountain in southern Oregon. Against a scenic backdrop far removed from the war raging across the Pacific, Mitchell and five other children would become the first—and only—civilians to die by enemy weapons on the United States mainland during World War II.

While Archie parked their car, Elsye and the children stumbled upon a strange-looking object in the forest and shouted back to him. The reverend would later describe that tragic moment to local newspapers: "I…hurriedly called a warning to them, but it was too late. Just then there was a big explosion. I ran up – and they were all lying there dead." Lost in an instant were his wife and unborn child, alongside Eddie Engen, 13, Jay Gifford, 13, Sherman Shoemaker, 11, Dick Patzke, 14, and Joan "Sis" Patzke, 13.

Though journalists had been stopped from reporting on the balloon bombs, after the deaths in Oregon, the War Department issued a statement describing them so that people finding debris knew not to touch it.

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

"They didn't have that luxury," Mikesh said. "They needed to launch them when they could."

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

Mikesh noted in his report on the balloons' legacy:

Historians have tended to make light of this use of man's oldest air vehicle, seemingly a pathetic last-ditch effort to retaliate against the United States. It was, however, a significant development in military concept, and it preceded today's intercontinental ballistic missiles launched from land or submarines. Had this balloon weapon been further exploited by using germ or gas bombs, the results could have been disastrous to the American people.  

Only two balloons were actually shot down by the U.S. military over North America. In one attempt, which was acknowledged years later as an error by the U.S. Naval Institute, they actually mistook a planet for the balloon. Posting on Facebook, they wrote: "When the USS New York (BB-34) was sailing towards Iwo Jima in 1945, the crew spotted a silver sphere flying high overhead that seemed to follow the battleship for hours. Concerned that the shiny orb might be a Japanese balloon weapon, the captain ordered it shot down. After the guns failed to score a hit, a navigator realized that they were attacking Venus."

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


"5 Attacks on U.S. Soil During World War II." History.Com, 30 Aug. 2018, Accessed 14 Feb. 2023.

"Balloon Bombs: Japan's Answer to Doolittle." National Museum of the United States Air Force, Accessed 14 Feb. 2023.

"Doolittle Raid." http://public1.nhhcaws.local/browse-by-topic/wars-conflicts-and-operations/world-war-ii/1942/halsey-doolittle-raid.html. Accessed 14 Feb. 2023.

Ibrahim, Nur. "Did Chinese-Sent Surveillance Balloons Fly Over the US During Trump's Presidency?" Snopes, 7 Feb. 2023, Accessed 14 Feb. 2023.

"Japanese Balloon Bombs 'Fu-Go'." Nuclear Museum. Accessed 14 Feb. 2023.

Mikesh, Robert C. Japan's World War II Balloon Bomb Attacks OnNorth America . Smithsonian Annals of Flight, 1973, Accessed 14 Feb. 2023.

Uenuma, Francine. "In 1945, a Japanese Balloon Bomb Killed Six Americans, Five of Them Children, in Oregon." Smithsonian Magazine, Accessed 14 Feb. 2023.

"When Japanese Balloons Threatened American Skies during World War II." Washington Post, 3 Feb. 2023. Accessed 14 Feb. 2023.

Nur Nasreen Ibrahim is a reporter with experience working in television, international news coverage, fact checking, and creative writing.