HCA: Hermit Crab Association

I have a hermit crab the went under his sand (below his food dish) about a month ago. today I dropped the tank lid in the tank and it narrowly missed the spot he molted in. I can see inside the cavern/hole he dug but it is too dark to make out anything even with/without a flashlight. what should I do? this just happened so I am unable to know if there is a smell or not so I can't find out If there's a rotting smell at the moment to conclude death

Humidity-75
size-roughly 1 1/2 inches
last molt- about 5 months ago
diet- apples and kale
molt duration- 1 month
lethargic before molt - No
losing libs before molt - No
Out of shell - no
Eating - yes
signs of sickness - No

Crabs will often move once underground - so there is a good chance he isn't in the same spot where he went down. Do you have deep substrate?

Your humidity is good at 75%. What is your temperature?

You will need to provide a more varied diet which includes protein and calcium daily. Be sure to read the Nutrition care sheet for info about the dietary needs of your crabs.

My substrate is not that deep and I can physically see his shell in there subtrase is only about 3. 1/4 inches deep

If you have other crabs, you will need to ensure that your molting crab is safe from being harmed by them. That's why it's important to have deep substrate, so they can tunnel underground to molt and be safe from other crabs.

He lives alone but has a neighbor in a different take right next to him. He out and about now