Mental Floss

Fu-Go Fire Balloons: Japan’s Last-Ditch Effort to Win WWII

Alma Katsu
A fu-go reinflated at California's Moffett Field in 1945. (The lines of the fu-go have been redrawn to make them easier to see.)
A fu-go reinflated at California's Moffett Field in 1945. (The lines of the fu-go have been redrawn to make them easier to see.) / Wikimedia Commons // Public Domain

Few Americans remember the tragic true-life incident at the beginning of my new novel, The Fervor (G.P. Putnam’s Sons), a reimagining of the Japanese internment during WWII. On May 5, 1945, the only U.S. wartime deaths on the mainland occurred when a fu-go, or fire balloon, exploded on Gearhart Mountain near Bly, Oregon. The explosion was responsible for the deaths of one adult (Elsie Mitchell) and five children (Dick and Joan Patzke, Jay Gifford, Eddie Engen, and Sherman Shoemaker) out on a picnic.

Although this was the only deadly encounter with a fire balloon, it was far from isolated: The U.S. military catalogued 285 incidents involving fu-go, mostly in the Western United States and Canada. However, few Americans know of them even to this day, and that’s because the Army stopped the media from reporting on incidents involving the balloons, not wanting word to get back to Japan, and to keep the American public from panicking.

Developing the Fu-go

It might seem odd that this firebombing incident came so late in the war—the Japanese surrender would happen a few months later, in September—but in fact, Japan had been experimenting with the idea of a fire balloon for years.

Japan had been looking for a way to retaliate against the U.S. for the Doolittle Raid, a daring aerial attack on Tokyo that took place four months after Pearl Harbor. The U.S. strike on Japanese soil so angered Japanese officials that they ordered the military to come up with a way to reach the U.S. mainland to incite panic, divert resources away from the war effort, and boost Japanese morale.

A Primitive Weapon

Today, we have sophisticated weapon systems such as precision-guided munitions and unmanned combat aerial vehicles. It’s all a far cry from the fu-go, which were primitive even for their time. One part optimism, two parts frustration, the fu-go program was the equivalent of putting a message in a bottle and throwing it into the ocean in the hope it would find its intended recipient.

The balloons were made not of rubber or vinyl but of a special type of rice paper. They had to be enormous, about 30 feet in diameter, to carry even a comparatively small load consisting of altimeters, batteries, incendiary bombs (to start forest fires), and an altitude-control ballast system. Hydrogen gas provided lift.

There was no navigational device aboard the balloons; instead, they relied on the jet stream, a natural phenomenon that had been discovered in 1926 by Japanese scientist Wasaburo Ooishi (one of the storylines in The Fervor) but had gone virtually unrecognized by the rest of the scientific community. (Ooishi, who wanted to reach as large an audience as possible, had chosen to publish in the universal language Esperanto—which even today isn’t popular.) The designers relied on faint signals from radiosondes, a battery-powered telemetry device that measures atmospheric parameters, to estimate how the balloons would approach the continental U.S.

The Failure of the Fu-Go

Despite the massive amount of work Japanese engineers poured into the program to overcome the limitations of technology and materials of the day, the fu-go had limited success, causing only a handful of small fires. Coincidentally, one balloon managed to hit some power lines in Washington state and cut off power to the grid's largest consumer: the Manhattan Project’s plutonium production plant in Hanford, Washington. A few balloons managed to travel as far as Michigan and Texas, however. The military examined debris and components from semi-intact specimens in order to determine exactly what these devices were and that they had, in fact, been sent by an enemy seeking revenge.

After the 1945 deaths in Oregon, the military finally spoke up about the balloons, noting that any encounters should be reported. Some balloons were found for a time after the end of the war, but there were no further deaths. (Old balloons are still occasionally discovered: In 2014, a fu-go that two forestry workers came across in British Columbia was destroyed by a navy bomb disposal team. Today, experts estimate there are still potentially hundreds of bombs scattered in remote areas of Western North America.)

One last interesting fact from the fu-go incident at Bly, Oregon: Reverend Archie Mitchell, husband to Elsie, would later marry Betty Patzke, sister to the two Patzke children who perished in the explosion. It seems Archie had only temporarily escaped a tragic end, as he would later disappear when, working as a missionary at a hospital for people with leprosy in Vietnam, he was taken prisoner by the Viet Cong and never seen again.

The cover of Alma Katsu's latest book, 'The Fervor'
The cover of Alma Katsu's latest book, 'The Fervor' / Penguin Random House

Set in the Japanese internment camps and inspired by the Japanese yokai, The Fervor holds the mirror of the past on the turmoil of the present and offers social commentary on injustices we’re experiencing right now. You can order it here.