My crab is out of its shell

Question
Hi i have four crabs and one of them Sandy is not in her shell anymore. She was buried i wanna say for a bout a month or so and i went to check on her this morning and saw that she had molted so i left her alone. I went to take a shower and by the time i came out i saw her by the salt water out of her shell!!!!! I became nervouse and didnt know what to do. I did some research and boiled the empty shells and then soaked them in the dechlorinated water. i left her in the same tank with the other crabs but put a barrier so that the other crabs cant get to her. She is still sitting in the salt water please help! Is she ok? Is she dying? I am very concerned and worried for her. These crabs are my classroom pets and if i return them with one less my students will be very sad. Please help.

Answer
It's not terribly uncommon for a crab to de-shell after a molt. If she's moving around there is hope. Pick her up and stick her butt end into the shell opening. Tap her lightly on her armor plate (the flat place behind her eyes) that should trigger her withdraw reflex.

Make sure your humidity and temperature are in the 74-82 range.