Gray tabby cat with blue collar and bell

I lost my gray tabby cat yesterday around 3pm near the Market Street Bridge by the Susquehanna River in Williamsport. He's about 9 pounds, short-haired with gray tabby fur, white paws, and a small pink nose. He wears a blue collar with a tiny silver bell, and he has a noticeable notch in his right ear. He can be wary of strangers but will purr if picked up. This cat means the world to me—he's a gift from my grandmother, and I'm really hoping to get him back.