Titanic tourist submersible goes missing with search under way

If you took a body down to 4000m slowly, not much would happen. Gas in cavities (lungs, stomach etc) would be slowly forced out. The chest and stomach would be compressed much smaller than normal, ribs would break. It would still look like a body and would be intact in the clothes probably.

With a sudden implosion it's like having a skyscraper dropped on your body from all sides. It's very energetic. You'd be pounded into mush. The air in cavities wouldn't have time to come out existing orifices, so it would burst holes through the nearest soft tissue. Imagine swallowing a grenade.

There also could be high temperatures for a split second due to the compression of air in the sub.

There will be remains, but they won't be pretty.

There are photos online of human remains after explosive decompression from the Byford Dolphin accident. I don't recommend looking them up. That's decompression so not the same, but very gruesome nonetheless.

Hotblack Desiato

The description on Wikipedia is grim enough. And that was only at a pressure of 9 atm.

kirk.

The blueprint for these vehicles was there

Think the MIR was something like 5" thick steel

Tried and tested

miamee

This was a fascinating read

https://www.newyorker.com/news/a-reporter-at-large/the-titan-submersible-was-an-accident-waiting-to-happen