All five aboard the missing Titanic submarine, discovered in bits after a "catastrophic implosion," were killed.

Washington: The U.S. Coast Guard announced on Thursday that a deep-sea submersible that was lost after a "catastrophic implosion" that killed everyone on board been found in pieces. The submersible was transporting five people on a trip to the century-old Titanic wreck.

U.S. Coast Guard Rear Admiral John Mauger told reporters that on Thursday morning, a robotic diving vehicle sent out from a Canadian ship discovered a debris field from the submersible Titan on the seabed about 1,600 feet (488 metres) from the bow of the Titanic, 2 1/2 miles (4 km) beneath the surface, in a remote area of the North Atlantic.

The Titan, a vessel owned and run by the US company OceanGate Expeditions, went missing on Sunday morning about an hour and a half into a dive that was supposed to take two hours to reach the world's most famous shipwreck.

The 22-foot (6.7-meter) Titan's tail cone and two pieces of its pressure hull were among five significant pieces discovered in the Titan's wreckage, according to Coast Guard officials. There was no indication of whether or not any human remains were found.

According to Mauger, the debris field in this location "is consistent with a catastrophic implosion of the vehicle."

There were no survivors among the five men aboard the Titan, including Stockton Rush, the company's founder and CEO, who was operating the Titan, according to a statement from OceanGate that was released before to the Coast Guard's press conference.

The other three were British nationals Shahzada Dawood, 48, and his 19-year-old son Suleman; British billionaire and explorer Hamish Harding; and French oceanographer and famous Titanic expert Paul-Henri Nargeolet, 77, who had visited the wreck numerous times.

According to the firm, "These men were true explorers who shared a distinctive sense of adventure, as well as a profound enthusiasm for exploring and conserving the world's oceans." "At this awful time, our hearts are with these five souls and every one of their families," the statement reads.

Teams of searchers and support staff from the United States, Canada, France, and Great Britain had spent days using planes and ships to scour thousands of square miles of open water for any sign of the Titan.

The aftermath of a considerably worse maritime calamity that resulted from the wreck of a migrant vessel off the coast of Greece last week, which killed hundreds of people, was virtually ignored by the intense global media coverage of the hunt.

VOICES FROM BELOW

When Titan met its end, according to Mauger, it was still too early to say. According to Mauger, search crews spent more than three days in the region with sonar buoys in the water but were unable to hear the loud, violent boom that would have been made when the submersible collapsed.

Yet, the Titan's last transmission and the location of the debris field relative to the shipwreck seemed to indicate that the breakdown happened on Sunday near the end of its descent.

Separately, the U.S. Navy admitted that its own acoustic data analysis had shown "an abnormality consistent with an implosion or explosion" close to the submersible's position when its communications failed.

Although not conclusive, this intelligence was immediately communicated with the search mission leaders, according to a senior Navy official who was initially quoted by the Wall Street Journal.

The Journal reported that the sound was picked up by a top-secret technology intended to find enemy submarines, citing anonymous U.S. defence officials.

Filmmaker James Cameron, who directed the Academy Award-winning blockbuster "Titanic," and who has personally travelled to the site in submersibles, claimed in a Reuters interview on Thursday that he learnt of the acoustic findings within a day and understood what it meant.

We've lost several buddies, I said in emails to everyone I know. The sub had sunk. It is currently in pieces on the bottom. I did that early on Monday," he recalled.

On Tuesday and Wednesday, sounds were detected by sonar buoys dropped by planes that briefly raised hopes that the Titan was still in tact and that her occupants were still alive and trying to communicate by hammering on the ship's hull.

Officials claimed that the sound study was inconclusive and that it was more likely that something else was making the noises.

According to Mauger, there doesn't seem to be any link between the noises and the position on the ocean floor.

AUTOS CONTROLLED BY REMOTE

It is unclear whether collecting the victims' remains will be possible given the nature of the disaster and the harsh conditions at those depths, but Mauger said robotic equipment on the seabed will continue to gather data.

During the course of the following 24 hours, we will start to demobilise personnel and warships from the scene, the admiral stated.

By Thursday, when the submersible's estimated 96-hour air supply was supposed to run out assuming the Titan were still in tact, the hunt had grown more desperate. But, the countdown proved pointless.

At Cape Cod, Massachusetts, and 400 miles (640 km) south of St. John's, Newfoundland, the RMS Titanic, which encountered an iceberg and sank during her maiden voyage in 1912, killing more than 1,500 people on board, is located.

According to the company's website, the submarine voyage to the wreck, which OceanGate has been doing since 2021, cost $250,000 per person.

A symposium of submersible industry professionals in 2018 voiced concerns about Titan's safety. Later that year, a lawsuit filed by OceanGate's former head of marine operations raised similar concerns.

Almost 10,000 square miles of ocean were covered by the extensive search. On Thursday, two specialist deep-sea robot vehicles were sent out to further the search into the ocean's depths, where the mission was made more difficult by extreme pressure and total darkness.

Due in part to the Titanic legend, the fate of the tourist submarine attracted attention on a global scale. Since the turn of the century, the "unsinkable" British passenger liner has served as the subject of numerous fictional and nonfictional works, notably the hugely successful "Titanic" film from 1997, which reignited interest in the tale.

Editing by Grant McCool and Stephen Coates; reporting by Joseph Ax and Steve Gorman; additional reporting by Rami Ayyub, Tyler Clifford, Richard Lough, Natalie Thomas, Edmund Blair, Ariba Shahid, Shivani Tanna, Caitlin Webber, David Ljunggren, William James, Steve Holland, Daniel Trotta, Brad Brooks, Gabriella Borter, Rollo Ross, and Idrees Ali.