>> it was one thing that any trip by humans to the bottom of the ocean tears constable risk. there are not many submersible vehicles that can even reach the depth where the titanic lies. that said, and it's jason carroll touched on in his report, there are specific questions about this specific vessel. in a moment, someone who took a test dive on it came back with questions of his own. but first, cnn gabe cohen. >> we are all in a position right now, saying what could we have done? >> will cohen, remembering back to 2018, when he said he penned a letter, first obtained by the new york times, t...