Death of a Crab

Question
I had a crab a couple months ago, who I came home to dead. I was never sure why he died.

He didnt' have a proper enclosure ( a plastic tub) but all his other needs were met. He had food pellets, cleansed tap water, climbing toys etc.

Anyways, I came home to him after a night+day of being gone, and I looked in his enclosure and saw there was another "rock" in his cage, a closer look showed it wasn't a rock. The crab had for some reason or another, crawled out of its' shell and my thought was that he dried out (without the humidity of a proper tank?). He had a large shell, if I thought he needed a bigger one, I certainly would have gotten him one, but i'm thinking that's why he crawled out initially.

Any thoughts?

Answer
Dear Ashley,
thank you for your question.
If you did not have a lid for the enclosure, this may well have been the cause of death. Land hermit crabs need a relative humidity of at least 70% and without a lid, there's no way to keep that up. Plastic tubs like Rubbermaid containers are perfectly fine if they are big enough, but you do need a lid (saran wrap will do for example, but since tghey are escape artist, a plexiglass lid is better).
It's very hard to tell why crabs die, though, unless you do something really important wrong. They may have internal parasites, they die easily from stress and sometimes they just die during a molt.

Depending on what species your crab was, he would have needed salt water. Purple Pinchers (Coenobita clypeatus) don't need it, but enjoy it. All the other species need it to survive.
Here are a few websites with excellent info on crab care:
http://www.thecrabbagepatch.com/
http://www.crabstreetjournal.com/
http://www.epicureanhermit.com/
http://www.hermitcrabassociation.com/
http://landhermitcrabs.com
I hope I was of some help to you
Jennifer