Debris located in the search for the missing Titan submersible is believed to have been from the sub, an expert has said.
And the company who own the sub, Oceangate have now said the crew are believed dead.
On Thursday evening OceanGate released this statement: "We now believe that our CEO Stockton Rush, Shahzada Dawood and his son Suleman Dawood, Hamish Harding, and Paul-Henri Nargeolet, have sadly been lost."
In a press conference this was reiterated by the US Coastguard.
David Mearns, who is a rescue expert and a friend of someone onboard has told Sky News "a landing frame and rear cover from the submersible" was recovered in the search area.
He said he received the information via WhatsApp from someone "directly connected" to ships involved in the search for the OceanGate submersible, the Mirror reports.
It is feared that the discovery of the debris indicates the vehicle imploded.
Earlier David Mearns had said: "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."
The Titan lost contact around 1 hour and 45 minutes into an eight hour trip to visit the Titanic wreck in the North Atlantic. Coast Guard officers have not said if they debris found is connected.
Admiral Sir James Burnell-Nugent, former Commander-in-Chief Fleet of the Royal Navy, added "the nature of the announcement suggests this debris is in some way connected with the Titan".
He explained: "There is of course a large debris field around the Titanic - and the various things we've seen retrieved from the Titanic have come from the debris field. It covers several hectares.
"But I think if this was Titanic debris, the Coast Guard would have made a distinction in the announcement. I think on balance this is probably grim news and suggests the Titan might have imploded under the immense pressure of the seawater while it was on its way down."
Finding debris raises the question of if the vessel was intact from the moment the search began.
Documents show OceanGate was repeatedly warned that there might be catastrophic safety problems posed by the way it was developed.
A major search operation was launched on Sunday as ships and planes rushed to the site with equipment to aid the search.
On Thursday, the US Coast Guard said an undersea robot sent by a Canadian ship had reached the sea floor, while a French research institute said a deep-diving robot with cameras, lights and arms also joined the operation.
The vessel was about 435 miles south of St John’s, Newfoundland, during a voyage to the Titanic shipwreck off the coast of Canada.
Founding member of the Board of Trustees of The Explorers Club, Hamish Harding, was on board the undersea craft, alongside UK-based businessman Shahzada Dawood and his son Suleman Dawood, who is a student at Strathclyde University.
OceanGate’s chief executive and founder Stockton Rush is onboard, as well as French submersible pilot Paul-Henri Nargeolet.
Sidonie Nargeolet, Paul-Henri's daughter said: "If they are not found, it will be very sad for us because we will not see him again"
"What he liked the most was to be in a submarine, (near) the Titanic. He is where he really loved being. I would prefer him (dying) at a place where he is very happy."
Nargeolet was a renowned diver.
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