Titanic submersible es morte

I think this is right, but I'm not sure. I do think the material they used though negates that possibility. Carbon fiber has very little flex or give to it unlike metals. So even a small fracture would have likely shattered the bubble so quickly that it becomes a non-factor.
I read a WaPo article this morning describing carbon fiber as a questionable choice when most submersibles are titanium. Apparently carbon fiber was used on this one because it allowed for a larger vehicle to accommodate guests, but one theory was that repeated dives and exposure to pressure gradually weakened the hull and that it was only a matter of time until a catastrophic failure occurred.