Miners always had to worry about gas explosions, cave-ins, and other disasters.
The workers battled a constant fear of disaster as they carried out their tasks
It is estimated that deaths caused by coal mine disasters reached a total of over 50,000 in Japan, approximately 20,000 of which belong to the Chikuho region.
It's been said from of old that coal mining is a battle against water and gas; in the same way, miners were daily fighting the battle with their own fears of disaster while working in pitch darkness deep in the bowels of the earth.
In the Meiji and Taisho eras, gas explosions, cave-ins, internal flooding, and fires were a concern even in mines that were comparatively shallow.
At the dawn of the Showa era, mechanization brought about a remarkable change in safety awareness as more and more safety equipment was introduced. However, mining activities intensified with large-scale operations and depth mining, and an increase in coal production was called for to meet the demands caused by the war. The amount of coal produced did increase, but it brought with it a good number of disasters.
As for disasters claiming 100 lives or more in the Chikuho coal fields, there was one at the Itoda-machi mine in Meiji 32 (1899), killing 215 people, and another at the Hokoku mine claiming 365 lives in Meiji 40. Also in Meiji 40, there was a disaster at Kaijima Onoura in Miyata-machi, Kurate killing 259, one in Taisho 3 (1914) at Mitsubishi Hojo in Hojo-machi killing 686 in (the largest incident in Japan's mining industry), one at Kaijima-kirino in Miyata-machi claiming 369 lives in the year Taisho 6, and another at Mitsui-yamano in Inatsuki-machi, Kaho, killing 237 in the year Showa 40 (1965).
A miner flung into the air by the blast
The Mitsubishi Hojo Coal Mine History shows the tragedy of the gas explosion with black smoke gushing and spiraling out of the air vents, the elevator cage blown 15 meters up into the air with shrapnel protruding through the elevator roof at the mine entrance. The victims' bodies are charred black with their skin all burnt, and even people walking on the surface within 200 meters of the mine entrance were knocked over by the explosion, the sound of which could be heard over six kilometers away.
As many families had both parents working in the mines, the disaster left well over a hundred orphaned children behind. This was taken as an opportunity to get the mining companies and workers to improve their safety awareness, resulting in the creation of the Safety Lantern Research Site by the Chikuho Coal Mining Association. Thus, formal safety research was finally begun in May of the 4th year of the Taisho era.
Working under such perilous conditions, it's no wonder that the religious sense of the yama folk was so strong.