In 2009, the Montana Supreme Court issued Baxter v. State, which cracked open the door to the legalization of assisted suicide and euthanasia in Montana.* A local doctor subsequently announced that he was actively killing or assisting to kill his patients. As far as I know, no one did anything to stop him.
Assisted suicide and euthanasia became de facto legal. Some of these deaths were presumably voluntary. In my personal experience from other states, deaths also occur on an involuntary or nonvoluntary basis, for example due to financial concerns. Adult children want the money right away and/or fear that mom or dad will change their wills, leaving the children with nothing.