In 1945, a Japanese Balloon Bomb Killed Six Americans, Five of Them Children, in Oregon

 

The military kept the true story of their deaths, the only civilians to die at enemy hands on the U.S. mainland, under wraps. 

In the months leading up to that spring day on Gearhart Mountain, there had been some warning signs, apparitions scattered around the western United States that were largely unexplained—at least to the general public. Flashes of light, the sound of explosion, the discovery of mysterious fragments—all amounted to little concrete information to go on. 

First, the discovery of a large balloon miles off the California coast by the Navy on November 4, 1944. A month later, on December 6, 1944, witnesses reported an explosion and flame near Thermopolis, Wyoming. Reports of fallen balloons began to trickle in to local law enforcement with enough frequency that it was clear something unprecedented in the war had emerged that demanded explanation. 

Military officials began to piece together that a strange new weapon, with markings indicating it had been manufactured in Japan, had reached American shores. 

They did not yet know the extent or capability or scale of these balloon bombs. Though relatively simple as a concept, these balloons—which aviation expert Robert C. Mikesh describes in Japan’s World War II Balloon Bomb Attacks on North America as the first successful intercontinental weapons, long before that concept was a mainstay in the Cold War vernacular—required more than two years of concerted effort and cutting-edge technology engineering to bring into reality. 

Japanese scientists carefully studied what would become commonly known as the jet stream, realizing these currents of wind could enable balloons to reach United States shores in just a couple of days. 

The balloons remained afloat through an elaborate mechanism that triggered a fuse when the balloon dropped in altitude, releasing a sandbag and lightening the weight enough for it to rise back up. 

This process would repeat until all that remained was the bomb itself. By then, the balloons would be expected to reach the mainland; an estimated 1,000 out of 9,000 launched made the journey. Between the fall of 1944 and summer of 1945, several hundred incidents connected to the balloons had been cataloged.

GRTWT.