Your parents are out of town for the weekend and your older brother throws a party. There are drunk people throughout the house and you don't know who half the people at the party are. What will you do? What are the risks

I would notify my parents first about the situation, not the snitch on your brother, but to inform them of what your status is and how you are doing. Safety is important during parties involving alcohol and party drugs, so involving your parents is a big help.
If the party gets too rowdy, and you are fearful of your safety and the safety of those in your neighborhood, then call the police in an effort to remove the rowdy drunk people.

Primary effectit is the most accurate.