I am PANICKING right now

I just went to check on my little 9 gram hoggie and he isn't in his tub He was there earlier this afternoon; I took a few pictures of him. His tub was closed. There is no top but it is tight against the shelf above it. He must have squuuuuueeeeeeezed out somehow.

I seriously don't know what to do. He is SO tiny. I've checked the rack, but this feels hopeless. I loved that little guy with all my heart. All I can think of is how anything I move could squish him and how hungry he must be (he was going to be fed tonight) and how impossible finding him will be.