It crashed through the treetops on the Vine Hill farm, and the only reason the bomb didn’t kill the farmer milking a goat was because it got snagged in the branches. Had it exploded, he would have been the first war casualty on American soil since Pearl Harbor. It was January 4, 1945.
The farmer called the sheriff and soon deputies, FBI agents and Army ballistics experts from Hamilton Field were speeding to that West County goat farm. None of them knew what they were handling – they didn’t even realize it was a live bomb, so they took it to the sheriff’s office and put it on display in the lobby.
All they knew was that it probably had been dropped from a balloon. “Hundreds of residents of western Sonoma county had seen the mysterious balloon sweeping inland from the vicinity of Jenner, highlighted by rays of the setting sun,” the Press Democrat later reported.
A couple of days earlier the PD had a front page story about the “mystery spheres” which had been found in Wyoming, Montana, Washington and Oregon. They were believed to be of Japanese origin, but the Army hadn’t confirmed that; all that was known for sure was that they carried incendiary devices. That story repeated speculation that the balloons were carrying enemy soldiers, which was the working theory for a couple of weeks: “There was no actual evidence that the balloon had carried enemy saboteurs but that seemed the only logical explanation for its arrival. It trailed an elastic cable that had been cut, possibly indicating that it once was equipped with a cage capable of carrying a crew of perhaps four or five who, on arriving over the United States, cut themselves free and parachuted to earth in a small-sized ‘invasion.'”
The same day the Vine Hill bomb landed, the Office of Censorship ordered a complete blackout of any balloon stories in newspapers and on radio. The curtain of silence remained in place until the war ended in August.
Pity Press Democrat editor Herbert Waters; this was the biggest local war story during WWII and he couldn’t write a word. He must have been gnashing his teeth when another balloon was spotted over Santa Rosa on February 23 and the crew of a Lockheed P-38 from the Santa Rosa Army Air Field (now the Sonoma County Airport) scrambled to shoot it down midair as it neared Calistoga – the first time one of the balloons was brought down by gunners.
Editor Herb surely was hopping mad that the PD couldn’t tell readers that three balloons came down in March – west of Cloverdale, near Guerneville, and close to the Mount Jackson quicksilver mine overlooking the Russian River Valley. Another turned up May 15 near Geyserville. There were probably frustrated screams in the newsroom as Waters learned one of the bombs blew a swimming pool-sized crater in a field near Santa Rosa (with people watching!) and another apparently started a fire close to Cotati. Sonoma Valley subscribers probably were irked because the paper didn’t mention some incident (a fire?) that occurred near the Heins ranch in Glen Ellen, or how El Verano schoolkids were all wound up about seeing that big balloon drifting overhead.
All in all, it’s believed at least ten balloons fell to earth in Sonoma county – more than anywhere else in the state.
Although authorities weren’t exactly sure what was going on, the Vine Hill bomb convinced the government that the U.S. was under some sort of air attack from Japan, and to say that the military in early 1945 was unprepared to handle it was an understatement.
The West Coast had never faced an active threat from Imperial Japan and slipped into a lack of readiness. The Navy and Army air bases in Santa Rosa were just used for general training, as was Hamilton Field; no combat planes were kept on ground alert anywhere on the coast; the long-range radar system wasn’t turned on most of the time; the civilian Ground Observer Corps was disbanded; most anti-aircraft artillery had been mothballed. Had Japan mounted a Pearl Harbor-like attack we would have been defenseless for hours.
The Fourth Air Force at Hamilton Field was suddenly thrust very much back into the war, with the critical mission to figure out what the hell the enemy was doing with those balloons. The very first one landed near San Pedro a couple of months before the Vine Hill bomb and was found to be carrying radio and meteorological equipment. Was it just a weather balloon which had blown off course all the way across the Pacific? A few other balloon fragments were found around the West and they thought they might be coming from Japanese relocation camps in the U.S. (remember, they were also wondering if the balloons were intended to carry a few men). Only when parts of a balloon were found at a bomb crater near Thermopolis, Wyoming did our best military minds realize that yep, this was a weapon.
A War Department memo listed six ways they feared the balloons might be used:
- Bacteriological/chemical warfare
- Incendiary and anti-personnel bombs
- Experiments for unknown purposes
- Psychological efforts to inspire terror and diversion of forces
- Transportation of agents
- Anti-aircraft devices
The immediate and overwhelming concern was not that the devices would blow up Americans but that they might set the great forests of the Northwest ablaze. There wasn’t an issue at the moment because it was still winter with its snow+rain, but if the balloons continued floating over through the spring and summer, it might divert thousands of soldiers from the warfront to fighting fires back home. To prepare, the Western Defense Command launched the “Firefly Project” which stationed 2,700 troops (including paratroopers) along with transport planes at strategic points.
The other top worry was the balloons could deliver some sort of bioweapon. Although the War Department’s specific fears weren’t listed, a payload of anthrax or plague could kill animals and people while grain smut (fungus) might wipe out America’s breadbasket – and Japan’s military was indeed thinking along these lines, as discussed in the next section.
To counter that threat the “Lightning Project” was launched to create an early-warning system for signs of unusual diseases in livestock or crops. Without explaining why this was so important, the Department of Agriculture quietly asked regional offices to stay in touch with veterinarians and ag workers down to 4-H clubs and report anything amiss. Remedies (presumably fungicides and sulfa drugs) were stockpiled throughout the West.
As weeks passed, an ever-increasing number of balloons were observed high over Sonoma County headed eastward (they were almost impossible to track via radar, as it turned out). They were now being found – usually in fragments after exploding, although also sometimes intact – from Alaska to Baja California. The farthest east a balloon travelled was Michigan, with the most active month being March. After censorship was lifted it was revealed that a group of the balloons were seen heading for San Francisco during the historic United Nations Conference, with one of them eerily hanging over the city for hours before drifting on. (The proper name for a group is a “festival of balloons,” but I applaud the wag who tweeted, “the collective noun for a collection of slow moving things filled with hot air is a ‘government.'”)
The only fatalities caused by the bombs happened on May 5 in Oregon, as the Rev. Archie Mitchell and his wife were leading five children on a fishing trip. An 11 year-old girl found the balloon in the woods and called for the others to come see. It exploded when one of the kids tugged on it, killing all of the children and the minister’s wife, four of them dying immediately. (The site is now memorialized by the Mitchell Monument.)
The government kept a lid on the news until rumors about the incident spread fear among southern Oregon loggers and campers; finally on May 22 the War Department and Navy issued a joint statement admitting the balloon bombs existed, but they weren’t a serious threat because the attacks were “so scattered and aimless.” They also initiated an educational campaign to warn against tampering with strange objects found in the woods. If that saved even one American life, the statement read, “…it would more than offset any military gain occurring to the enemy from the mere knowledge that some of his balloons actually have arrived on this side of the Pacific.”
Had the Mitchell tragedy occurred a month earlier, it’s possible WWII might have gone on longer – with the United States suffering many civilian casualties, particularly in places like Sonoma county. But Japan had ended the balloon bomb program in mid-April, convinced that it had been a complete failure, mistakenly assuming almost none of the devices actually reached America. In truth, about 10% of the 9,300+ balloons are believed to have reached North America – exactly as the Japanese engineers predicted.
It turned out that the War Department’s censorship was a brilliant move. The Japanese high command indeed had been scanning media reports from Russia, China and the U.S. looking for any news, but all they found was a single report about that explosion in Thermopolis, Wyoming.
The Japanese military had been tinkering with the idea of a balloon weapon since 1933, considering designs which would drop bombs or shower propaganda leaflets behind enemy lines after flying a fixed distance, as well as a balloon large enough to carry a soldier. Nothing apparently went past the drawing board until the Doolittle Raid in April 1942, which made Japan hungry to inflict damage on the American mainland. The best they could do was starting a minor forest fire near Mt. Emily, Oregon five months later, using a small bomb-carrying airplane launched from a submarine. That morphed into the 1943 plan of using subs off the coastline to inflate and launch balloons with a timer-release bomb. That plan was dropped later in the year as all submarines were pressed into service delivering weapons and food to soldiers fighting on Pacific islands.
The only option left was to launch balloons from Japan itself, 6,200 miles away from North America. Problem was, the jet stream winds were still poorly understood; the estimated time for a balloon to reach the West Coast ranged from 1-4 days, making any sort of timer useless. For more than a year they experimented with a couple of hundred balloons carrying radio transponders, none of them intended to reach the U.S.
The result of their multi-agency research project was the “Fu-Go” balloon bomb (a code name which roughly translates as something like, “Weapon Model B”). It was designed to fly between 30,000-38,000 feet, cutting loose ballast when it dropped too low and releasing hydrogen when it ascended too high. When all the ballast sandbags were gone it released the incendiary and TNT bombs, then blew up the balloon. All of this was done without electronics, of course; Wikipedia has a clear explanation of the balloon’s ingenious control system.
Wikipedia also cites a couple of non-translated documents which apparently state there were plans to use the Fu-Go to release anthrax and plague (Yersinia pestis), although the definitive Mikesh report (see sources) says, “though possible, the Japanese did not consider this aspect.” But as they were preparing to cancel the Fu-Go project thinking it a failure, a plan called “Operation Cherry Blossoms at Night” was finalized; this called for kamikaze attacks on the Naval base at San Diego with the planes carrying ceramic jars of plague-infested fleas. The war ended before the operation could be carried out.
While all mention of the balloon bombs was suppressed in America, Japanese propaganda news agencies were telling their domestic audience that the balloons were causing havoc in the U.S. and starting numerous fires plus killing 10,000 casualties. After the Mitchell tragedy was revealed (which happened after the last Fu-Go was launched, remember) they made English-language broadcasts claiming the balloons had been only used on an experimental scale and were the “prelude to something big.”
Finally, Gentle Reader may be surprised to learn there’s even a few Believe-it-or-Not! items to our story because so many found the balloons and/or the ordinance and didn’t know what it was. Authorities in Elko, Nevada, were startled to find an old prospector come into town with a still-inflated balloon tied to his burro – he thought the government “had lost something.” In Yakima, Washington a boy had an anti-personnel bomb which he had been carrying around for several days. Ranch hands at Yerington, Nevada came across a balloon with its attachment; they tied it to the bumper of a car and towed it to a garage. The guys wrote a letter to authorities about it but heard nothing back, so they deflated the balloon and used it to cover a haystack. When the state police finally came calling they found there were still two live bombs.
Details about the Vine Hill bomb and other Sonoma county incidents were released when censorship was lifted and appeared in the Press Democrat on August 16, 1945 and a UP wire service story in the Petaluma Argus-Courier August 17. Details of the Mitchell incident are from the Associated Press datelined May 31. The definitive document on the Fu-Go balloon bombs is Japan’s World War II Balloon Bomb Attacks on North America by Robert C. Mikesh, Smithsonian Institution Press, 1973, and all other details in this article are summarized from his report except as noted.