An expert appeared hopeless about the rescue of the five men in the submersible suggesting they most likely had an immediate death.
It comes as the US Coast Guard announced that a "debris field" has been found in the search area for the Titan submersible that went missing during an expedition to the Titanic wreck Sunday, with five people on board.
In a chilling statement, the expert suggested that the term "debris field" implies that there have been no survivors and claimed the submarine most likely imploded.
David Mearns, a rescue expert who is friends with two of the men onboard, told Sky News: "They don't use phrases like 'debris field' unless there's no chance of a recovery of the men alive.
"A debris field implies a break-up of the submersible ... that really sort of indicates what is the worst-case scenario, which is a catastrophic failure and generally that's an implosion."
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However, the expert claimed that in that case, at least the death of the people on board must have happened instantly, and the description of a "debris field" is an important use of phrase.
He told the broadcaster: "A debris field implies there's a break up of the submersible and at that depth, because we know that they lost communications at around 3,300m… so that really indicates what is the worst case scenario which is a catastrophe failure, an implosion."
He added: "The only saving grace is that it would have been immediate - literally in milliseconds - and the men wouldn't have known what was happening."
He added: "The only saving grace is that it would have been immediate - literally in milliseconds - and the men wouldn't have known what was happening."
The search operation took a bleak turn when the US Coast Guard said a debris field was found at the bottom of the ocean near the Titanic.
The announcement came after the critical 96-hour mark when breathable air could have run out.
The Coast Guard’s post on Twitter gave no details, such as whether officials believe the debris is connected to the Titan, which was on an expedition to view the wreckage of the Titanic.
It said the debris was discovered within the search area by a remotely operated underwater robot, and was being evaluated.
However, Mr Hearns then went on to tell Sky News he had received confirmation the debris was from the missing submersible.
Mr Mearns told how he received a WhatsApp from someone "directly connected" to the ships involved in the search, who told him "a landing frame and rear cover from the submersible" was recovered.
He said: "There is a WhatsApp group between ourselves and the explorers club, that we have all been connected to as soon as this happened, and our President is directly connected to the ships that are out there, and the message they are telling me 'if you are talking about debris, it was a landing frame and rear cover from the submersible'."
He added: "So again, this is a very unconventional submarine, that rear cover is that pointy end of it, and the landing frame is the little frame that it seems to sit on, and that is how its docked into the landing bit, so that confirms it's the submersible."
The Titan was estimated to have about a four-day supply of breathable air when it launched Sunday morning in the North Atlantic — but experts have emphasized that was an imprecise approximation to begin with and could be extended if passengers have taken measures to conserve breathable air. And it’s not known if they survived since the sub’s disappearance.
