Lots of ways to die in Yellowstone. Not knowing where, and hanging out close to the collection of toxic outgassing from the fumaroles and volcanic caldera structures is very possible. Falling into one of the superheated water ponds is another.
“Death in Yellowstone” by Whittlesey is a book worth perusing.
With 4 3/4 MILLION visitors a year, there’s going to be some idiot in there somewhere that kills himself by stupidity.