Navy blue evening gown with detachable silver belt

I lost my navy blue floor-length evening gown yesterday around 7:30pm after a fundraiser at the Temple Theatre on Main Street in downtown Saginaw. It's a size M chiffon gown by Calvin Klein, with a detachable silver sequin belt and a small sapphire crystal brooch perched on the left strap. The gown is in good condition overall, but there’s a tiny snag along the hem about 1.5 inches from the bottom and a faint coffee stain on the inner lining that only shows when you lift the fabric. It has sentimental value—my grandmother gave it to me for a milestone anniversary, and I really need to get it back. If you found it or picked it up somewhere nearby, please drop me a line; I’d be forever grateful.