HCA: Hermit Crab Association

I bought a couple PP's a few months ago, the furst two I bought together were Krill and Rangoon, Rangoon buried himself a couple days after I got him and hasnt come up since. I have a new crab now, Cheeto, so Krill doesnt get lonely.
Since then Krill has gone down for about a month and half and just came back up (presumably molting). My question is if I should go diging to fetch Rangoon out or if they have eaten him (they did drag his shell up from their tunnels) or generally what my next steps should be.

Thank you for any advise!

Are you certain that it was the molting crab's shell? And not one of the other extras you have in the tank?
Crabs go through a lot before we get them, and sometimes they aren't able to survive it. If he didn't have enough energy to complete his first molt with you, he may have simply died underground - he may not have been killed or eaten by the other crabs. If there are no crabs underground, you could dig and look for him for peace of mind - a dead crab underground won't be harmful to the other crabs. Also keep in mind that with the heat and humidity, crabs decompose quickly and you may not find him.