There is always a chance of trouble whenever alcohol &?people under 21 are mixed into the college town setting. Will you be accused of furnishing alcohol to minors? That depends on many factos, some of which you cannot control. Best advice if you really fear this is to avoid the sotuation or if you cannot or will not , then to not drink alcohol or get high while attending so that you are in control of your own faculties typically,if it is not your residence you will not automatically be assumed to be furnishing to minors ...
I agree with Mr. Tauber. I hate to use the cliche "guilt by association" bu I've seen it happen in scenarios just like the one you have described. You could be accused of furnishing the alcohol to minors, contributing to the delinquency of a minor, or be accused of hosting either a disturbing party or hosting a party with underage drinking. In the end, the risk is not worth any benefit that would be derived. If there are underage people drinking or if you just think there is the slightest possibility that that might be occurring, it is best to stay away. It will be better in the long run.
As an adult with minors (under age 17) present, you could be misunderstood and possibly charged as "contributing to the delinquency of minors" which is a criminal offense.
MCL 750.145 provides: Contributing to neglect or delinquency of children—Any person who shall by any act, or by any word, encourage, contribute toward, cause or tend to cause any minor child under the age of 17 years to become neglected or delinquent so as to come or tend to come under the jurisdiction of the juvenile division of the probate court, as defined in section 2 of chapter 12a of Act No. 288 of the Public Acts of 1939, as added by Act No. 54 of the Public Acts of the First Extra Session of 1944, and any amendments thereto, whether or not such child shall in fact be adjudicated a ward of the probate court, shall be guilty of a misdemeanor.