You might want to contact the Minnesota Health Department tomorrow and talk with them. They can tell you if there are any laws, and what they are, and how to go about obtaining an involuntary commitment.
Each state is different. Some you have to go to court first and have them declared "incapacitated" and unable to handle their own affairs and get someone (preferably family, but sometimes not) appointed guardian. So check with Minnesota Health Department, if they don't know, they will probably know who to send you to that does.
In some states if they have threatened suicide or have been violent to themselves or others they can be held on a 72 hur to 8 day 'evaluation hold.' I do not know if that law is on the books in Minnesota.
Found this:
http://nami.beardog.net/AdvHTML_Uplo...Commitment.pdf
You can download that to your computer and then increase the font size for easier reading, lol
and this:
http://www.psychlaws.org/legalresour...otastatute.htm
Hope what Prodigal gave you and the above helps. It should get you started in the right direction.
Love and hugs,