Blue Tang Dead - Trapped inside a Rock Wedge

[accel]

So yesterday I was with a friend helping him clean the tank and learn more about his process. We were surprised to see his Blue Tang trapped and dead within a rock wedge.

He said the fish were all fine the night before--meaning everyone is still actively eating. He did notice the blue tang started scratching which we both think is ICH

But is it possible that this fish will die the following day that quick? When we recovered him, he was literally trapped with a rock wedge so we thought he got trapped and can't get out. He probably violently moved around and scratch his body. We saw deep scar marks that kind matches the coloration of the rock when we took him out.

There are no crabs around. There's chromis and clownfish.
We took a photo here
https://ibb.co/eEMaSH

Any idea what killed this tang that quick?

 

[accel]

Here's a close up of the belly

https://ibb.co/mi05ux

 

[Tripod1404]

Nope, fish do not get trapped. Blue tangs are known to wedge them selves when stressed, sleeping or sick. It probably was sick and went there to die peacefully.

 

[crawlerman]

Mine wedges in the rock about 1 hr before lights out every night. I doubt he got stuck. If it's ich or velvet, others will soon follow.