A large debris field containing multiple sections of the vessel were spotted earlier in the day by a remotely operated vehicle (ROV) scouring the seabed near the Titanic wreck site 400 miles south of St John’s, Newfoundland, officials said at an afternoon press conference in Boston.
“The debris is consistent with the catastrophic loss of the pressure chamber,” R Adm John Mauger of the US Coast Guard told reporters.
“We immediately notified the family on behalf of the US Coast Guard and the entire unified command. I offer my deepest condolences to the families. I can only imagine what this has been like for them.”
The announcement marked a heartbreaking end to a giant international air and sea search for the sub and its crew. The 22ft (6.7m) sub went missing on Sunday, one hour and 45 minutes into its scheduled 11-hour dive.
Mauger said it was too early to tell exactly when the implosion occurred, but noted that nothing was detected on sonar buoys deployed in the ocean in recent days.
“I know there’s a lot of questions about why, how, when this happened,” he said.
“This is an incredibly difficult and dangerous environment to work in out there, but those questions … are going to be the focus of future review.”
He was unable to say if attempts would be made to recover the bodies.
Those aboard the submersible were British adventurer Hamish Harding, 58; French veteran Titanic explorer Paul Henri Nargeoloet, 77; British-Pakistani businessman Shahzada Dawood, 48, and his 19-year-old son Suleman; and 61-year-old American Stockton Rush, co-founder of OceanGate, the company that operated the lost sub.
The company acknowledged their deaths in a statement posted to Twitter. “These men were true explorers who shared a distinct spirit of adventure, and a deep passion for exploring and protecting the world’s oceans,” it said.
“Our hearts are with these five souls and every member of their families during this tragic time. The entire OceanGate family is deeply grateful for the countless men and women from multiple organizations of the international community who expedited wide-ranging resources and have worked so very hard on this mission.”
Richard Garriott, president of the Explorers Club, of which Harding and Nargeolet were members, said he was “heartbroken for the families, friends and colleagues of those who were lost”.
He said in a statement the club was grateful “for all our members and the scientific and exploration community around the world who have mobilized personnel and resources to support the search and rescue”.
Garriott described Harding as a “dear friend” to himself and the club. “He holds several world records and has continued to push dragons off maps both in person and through supporting expeditions and worthy causes,” he said.
Harding and Nargeolet were “both drawn to explore … in the name of meaningful science for the betterment of mankind”.
The breakthrough in finding some of the remains of the Titan came from the deployment of deep-ocean ROVs for the first time on the fifth day of the search after their arrival by sea.
A vehicle from the Canadian vessel Horizon Arctic was the first to reach the seabed on Thursday morning, the Coast Guard said, joined later by another from the French ship L’Atalante.
Carl Hartsville of the Woods Hole Oceanographic Institution told the briefing the debris was located approximately 1,600ft from the bow of the Titanic, which sank in 1912, and there was no indication of a collision with its wreckage.
“It is a smooth bottom there. To my knowledge and [from] anything I’ve seen there’s no Titanic wreckage in that area,” he said.
“It’s consistent with the location of last communication for an implosion in the water column. The size of the debris field is consistent with that implosion in the water column.”
Hope of finding the crew alive was already fading on Thursday with the knowledge that the 96-hour oxygen supply inside the submersible, had it still been intact, was set to expire.
There had also been no further reports of “banging” noises picked up on Tuesday night and Wednesday by sonar buoys dropped by Canadian military aircraft, unidentified sounds which are now believed to have been unconnected.
Favorable weather conditions at the search site were helping the effort, with rescuers “making the most of this weather window”, the coast guard said.
The safety record of OceanGate, and the ability of the Titan sub to withstand massive pressure at depths of more than 12,000ft, have been called into question in recent days, with industry experts and former passengers expressing concerns.
Nicolai Roterman, a deep-sea ecologist and lecturer in marine biology at the University of Portsmouth, UK, told the Associated Press that the Titan’s disappearance highlighted the danger and uncertainties of deep-sea tourism.
“Even the most reliable technology can fail, and therefore accidents will happen. With the growth in deep-sea tourism, we must expect more incidents like this,” he said.
Deep-sea exploration expert Mark Martin told CNN that the reported loss of the Titan’s passengers was tragic. “It’s not something any of us really want to dwell on. I really don’t have much hope that there’s going to be any rescue, and in my opinion this is a recovery at this point,” he said.
The family of Harding, a British explorer onboard the Titan, criticized OceanGate for waiting hours to alert the coastguard on Sunday after realizing the sub was out of contact.
“It’s very frightening. [It] took so long for them to get going to rescue [them], it’s far too long. I would have thought three hours would be the bare minimum,” Kathleen Cosnett, Harding’s cousin, told the Telegraph.
According to the accepted timeline of events, the support ship Polar Prince lost contact with Titan at about 9.45am ET on Sunday, but the coastguard did not receive the first report that it was missing until 5.40pm.
