One facility of a hot spring was partly exploded in Shibuya-ku, Tokyo. I was surprised that there are a lot of hot springs in Tokyo. Essentially hot springs spring from the ground. Hot springs are natural products, but in Tokyo they were dug deeply into the ground.
They say that it's pretty dangerous, because methan gas gushes at the same time. It's said that in this case methan gas was exploded by unknown cause. These hot springs are places of relaxation for the people in Tokyo, but they have danger.
Are they true hot springs? Maybe they are pseudo-hot springs, but even in traditional and famous hot springs illegal actions have been done. For example they are coloring or dilution.
Japanese like hot springs, but now we have too many hot springs. We can't understand where true hot springs are. It's good that many people can relax, but now we need to turn our attention to the gas explosion.