Explosion accident

Yesterday, an explosion accident happened at hot spring facilities in shibuya. Three women died of this accident. It is thought that it is because the methane drawn up underground ignites. I saw the image of the accident spot on the television. That was a very miserable sight. I shocked very much because such an accident happened in my familiar place.However, a similar accident seems to have happened several times before. I worry about whether the accident happens again because the number of hot spring facilities has increased in the city recently. I think that we should sutudy of the safety of these facilities more.