I saw a video on TV where they tested what happened when an old time diving suit would lose pressure underwater.
The air was supplied from above through a tube.
Occasionally there would be a catastrophic failure and loss of air pressure, and they would find a good portion of the body crammed up inside the diving helmet.
This was at less than 200 feet.
This is 2 miles down.
7700+ psi. Nasty nasty stuff.