Gray dwarf hamster in blue travel cage

I lost my gray dwarf hamster Gizmo yesterday around 3pm near the Columbia Public Library on Broadway Ave. He’s a tiny guy, about two inches long, with soft gray fur, a white belly, and a small heart-shaped patch on his chest. He was in a blue plastic travel cage with a wheel and some shredded tissue bedding. I last had him in the living room, but the window was open and he might have squeezed out. I’m really worried—he’s a sweet little guy and this cage is his home; he has sentimental value to my kid. If anyone finds him, please text me and I’ll come right away.