Black leather Tumi briefcase with silver clasp

I lost my black leather Tumi briefcase yesterday around 3pm near the Renaissance Center on Jefferson Ave in downtown Detroit. It's a medium-sized case with a slightly worn bottom corner, and the leather still shows a subtle grain. Inside there's a blue notebook, a USB drive, and a stack of client files, plus a red leather luggage tag with my initials 'AR' and a small dent on the silver clasp that bears the Tumi logo. The case is important for work and has sentimental value—it was a gift from my dad. If you've seen it, I’d really appreciate getting it back.