molting and mites (please answer quickly)

Question
My crab lost its exoskeleton a few days ago, and seemed to be just surface molting.  Then I noticed a lot of mites crawling all over it, and the pet store said it was probably dead.  Last night it crawled out of its shell, and there are still some mites around it, but it appears to be dead (it is VERY still).  I have just put some water and grapes (its favorite food).  What else should I do?  My 5yo is very distraught :(
Thanks!

Answer
If he passed you should notice a really bad fish type smell.

If he's alive, it would be best to get rid of the mites. You'd need to take out everything in the tank. Anything plastic wash it, throw away the substrate and get new substrate. You'd need to bathe the crab in double strength aquarium salt water to kill the mites. Scrub out the tank and make sure no mites are hiding in the corners.

For more information on land hermit crabs feel free to visit this website.
www.hermitcrabaddiction.net/forum