We're left to speculation without accurate modeling and conditions.
The ends off the middle has me looking towards the retention of the ends originally.
Seems there were a metal ring each end.
Were they involved in where material began to fail first?
Was material stressed there from prior dives and returns and pressure fluctuations?
Doesn't matter now in this case that material stressed to fail near reinforced areas including rings or ridges still fails anyways.
Explorers and those who follow are seldom those designing and building craft. Yes they can offer input. If they stayed in a building and built craft they'd travel less. If they afford both activities of collect sponsors for both. If they were all engineers. Which want mechanics or others to actually build.
I can almost understand how someone could over trust someone else's build(s). My limited part building parts components for autos though inspired less trust myself.
Where that faith is based can always be suspect. But certainly personal too.
Each person could have had faith in something different.
One in a partner , (fellow rider or relative). Another the pilot. Another the craft itself somehow.
And maybe another just in beating the odds of risk as before . Again. A trend and part of what he/they did.
Craft failed . We'll here more. Hind site precautionary I / we told you so kind of stuff I suspect .
A professional saying a bumblebee shouldn't fly or something. Therefore, a laundry basket isn't suitable for deep dives. Though the right one should tolerate the pressure better.
Somewhere more risk is being undertaken for varied reasons. Almost but not quite regardless.. Some for more casual reason ; than others. And the most desperate ones running on hope; (it could work out positively) more than faith ; (Belief in an unseen ability /result) Except those running on faith alone.
And the worst turning into no hope or faith. Given the chance to recognize failure...
And all based on risk.
Low to high.
My voluntary risk taking chicken out point is on that line from low to high somewhere. We all have one. But those points vary with the individual given a choice.
But recognizing risk and amount vs where we should re evaluate our next choice? Can be where we err. Hard to judge where others should cut thier potential losses (if they can) when we struggle with our own.
Climb in a man made container and leave our human sustaining environment. There will certainly be risk.
Nixon had a speech written for him should our astronauts not make it back. knowing there was the risk. A decent speech. But an acknowledgement of failure dressed up to try to comfort the living relatives and fellow citizens reaction to the risk overwhelming the risk takers. Expanded to any empathetic nerve.
https://www.space.com/26604-apollo-11-failure-nixon-speech.html
Who has a speech for this subs passengers? Is one needed?
They are not trained astronaut memorial material. They were voluntarily poised to peek through a window in a foreign environment not friendly to humans. And paying one way or another for the privilege. Before paying the highest personal price.
Travelers not knowing thier final trip's beginning ; and beginning of thier final end's was the same thing?
Literally signing prior that they acknowledged the risk of death.
Without seeing a real time meter chart or graph indicating the odds of that risk? (Or a future risk pre dive amount of risk.) Did quality and design and materials factor in the failures timing?
no one would be expected to go if it was known?
Going or not. Individual chicken out point based on what? A real or perceived or prior not a concern of being too serious risk?
Risk took the whole hand. Regardless of the prior dives /attempts proven odds.
It happens.
Look for the inspector sticker and figure out if the inspection was suitable I guess..