They are likely lost forever. Even a pinhole at depth puts enough pressure into the cabin to liquify everyone inside moments before the external pressure crushe

They are likely lost forever. Even a pinhole at depth puts enough pressure into the cabin to liquify everyone inside moments before the external pressure crushes the vessel like an empty can of soda. Assuming it was not a loss of pressurization or hull related failure - say it was electrical or mechanical, it is very cold i̶n̶ s̶p̶a̶c̶e̶ on the ocean floor.