After more than a year of work and more than a month of refinement, Kalamazoo City Commissioners have approved an ordinance that seeks to crack down on underage drinking and partying. The ordinance reinforces state rules that make it a criminal offense for an adult to allow minors to use drugs or alcohol on their property. The rules come with an 18-month sunset clause, at which point the commission will consider whether to re-enact it, refine it or outright reject it.