I had both of mine replaced in Bumrungrad Hospital, Bangkok. With no problems and a quickish recovery on both of them. Would recommend them any day. Surgeon was a Dr. Panya, very good.
Looks like an NGV conversion not LPG. Storing cylinders like that is not the way to do it.. There are way to many accidents in Thailand of single story buses converted to two stories. Doesn't work.
Don't disagree with you but from 1st hand experience it sounds like the LPG in the cylinder did a 'BLEVE' most likely from being exposed from an adjacent gas flame. Quite common here.