A new Illinois law that punishes adults who host parties with underage drinking at their home is taking effect Tuesday. The legislation makes it a Class A misdemeanor to host or allow gatherings where teenagers drink alcohol. Fines will be at least $500. It's a Class 4 felony if the underage drinking results in injury or death. Adults who discover minors drinking alcohol on their property won't be charged if they call the police to help put a stop to the party.