A doctor has described what would have happened to five people aboard the Titan submersible when it suddenly imploded.
Dr Dale Molé, a former Navy doctor, claimed that the final moments for the crew of the submarine would have been quick and painless.
He said: "It would have been so sudden, that they wouldn't even have known that there was a problem, or what happened to them.
"It's like being here one minute, and then the switch is turned off. You're alive one millisecond, and the next millisecond you're dead."
Tributes poured in for the five people aboard who were killed while on an expedition to the Titanic wreck at the bottom of the Atlantic Ocean.
Those killed were Stockton Rush, the CEO of OceanGate Expeditions, two members of a prominent Pakistani family Shahzada Dawood and his son Suleman Dawood, British adventurer Hamish Harding and Titanic expert Paul-Henri Nargeolet.
The announcement that no one survived Thursday brought a tragic end to a five-day saga that included an urgent around-the-clock search for the vessel known as the Titan.
But Dr Molé explained that the crew would not have realized there was a problem or what was happening to them.
He said: "They would have been ripped to shreds. An implosion is when the wave of pressure is inward, whereas an explosion is when the pressure wave or the shock wave goes out from whatever the source of that is."
The pressure chamber of the submarine, which held the occupants, was protected by a sealed pod and a pressurized gas system.
However, it appears that the carbon fibre cylinder of the pressure vessel gave way, resulting in the implosion.
The doctor explained that the implosion would have been violent and instant, as high-pressure water flooded into the submarine, tearing apart the hull and crushing those inside.
He told the Daily Mail: "The pressure hull is the chamber where the occupants reside. It sounds as though they had reached the bottom when the pressure vessel imploded, and usually, when it gives way, it gives way all at once.
"When somebody stands on an empty soda can, it would support your weight, but then if you press on the sides, the can would collapse immediately.
"It's simply where the debris and fragments and everything else goes inward because of a strong external force. In this case, it was the ocean."
"At least at the depth of the Titanic, which is 12,500 feet, the external pressure would be 6,000 lbs per square inch.
"It's that pressure that, if there were a weakness in the hull, would cause the hull to collapse and suddenly creates a shockwave. An implosion can certainly be every bit of destructive as an explosion."
The Titan launched at 6am Sunday and was reported overdue Sunday afternoon about 435 miles (700 kilometres) south of St. John’s, Newfoundland.
Rescuers rushed ships, planes and other equipment to the site of the disappearance, however, any sliver of hope that remained for finding the crew alive was wiped away early Thursday, when the submersible’s 96-hour supply of air was expected to run out.
The Coast Guard later announced that debris had been found roughly 1,600 feet (488 meters) from the Titanic.
Tributes to and praise for the searchers who tried to save them poured in from across the globe.
Harding’s family said in a statement: ”He was one of a kind and we adored him... What he achieved in his lifetime was truly remarkable and if we can take any small consolation from this tragedy, it’s that we lost him doing what he loved.”
In a statement beginning with a Quranic verse, the Dawood family thanked rescuers: “Their untiring efforts were a source of strength for us during this time, We are also indebted to our friends, family, colleagues and well-wishers from all over the world who stood by us during our need.”
A longtime friend and colleague of Nargeolet told French media that when contact was lost Sunday, he quickly feared the worst.
“Unfortunately, I thought straight away of an implosion,” diver and retired underwater filmographer Christian Pétron said Friday to broadcaster France-Info. At the depths in which the submersible was operating, the pressure is intense and unforgiving, he noted.
“Obviously, the slightest problem with the hull and its implosion is immediate,” Pétron said.
