She keeps bringing up the issue of criminal ghosts. I'm not sure if I misunderstood previous canon, but if doesn't that mean they were already sentenced by Shiki and in hell? I know I should blame Komachi but I don't know if criminal ghosts means, "Ghosts of bad people" or "ghosts of the damned"
I think she's more concerned about evil spirits, and that 'noxious gas being harmful to people' is just excuse.
It's not like it was made to be used as a hot spring, but......well, I suppose I'd better put up a warning sign so people looking for a hot spring don't die.But Old Hell's vengeful ghosts...Because it's filled with sulfurous gases that are poisonous to humans.*cough*Dangerous?...er...If it's a sign you want, I've already put one up.