This book has been around for almost two decades but finally had a chance to read it. The first chapter is dedicated to incidents involving hot springs so may be of interest if you are into reading. Not for those with a light stomach. The springs in that park average around 200F in parts and are dangerous as can be, although there is one area that is acceptable for soaking inside park boundaries I'm aware of, only one. When I visited it last three years ago in May (opening week) it reminded me that I maybe shouldn't be there, as you are on top of the only super volcano on the continent and it's somewhat unnatural to have the ground boiling on the hiking trails.
Anyways, the book focuses mostly on ignorance of the public when it comes to our wilderness areas, which have resulted in death. Some of the stories make you shake your head, like parents that place their kids on a bear for a photograph. People's stupidity can never be underestimated and it goes way back to the 1800s. There was a brief mention of one man who sued a national park after being struck by lightening within the boundaries. As you can imagine the constant battles between lawyers and rangers have resulted in the many prohibitions and warning signs to compensate. Hopefully the day will not come where all areas will be blocked off.
http://www.goodreads.com/book/show/432684.Death_in_Yellowstone