I really hate to mention the nuclear option but involuntary commitment is better than death. If it is really obvious, it doesn't require filing anything, just reporting it to the right agency for an intervention. That may be the police or possibly other authority. Your local mental health facility or health department or crisis assessment center would know who you should call. Short term and maybe long term they are not going to be happy with you if you do this. Think it through and be sure you really think it warrants it before doing it.