Missing Titan sub suffered 'catastrophic implosion,' passengers believed dead

The missing tourist submersible that was bound for the Titanic wreckage site suffered a "catastrophic implosion" in the ocean's depths, the US Coast Guard said Thursday, bringing a tragic end to the search for the five people on board.

A remotely operated vehicle found the Titan submersible's tail cone on the seafloor roughly 1,600 feet (488 meters) from the bow of the Titanic, Coast Guard Rear Adm. John Mauger told reporters in Boston, Massachusetts.

Additional debris that was discovered near the site was "consistent with the catastrophic loss of the pressure chamber," he said.

"Upon this determination, we immediately notified the families on behalf of the United States Coast Guard and the entire unified command. I offer my deepest condolences to the families," said Mauger.

The Titan went missing Sunday after plunging below the ocean's surface, bound for the Titanic's remains, with four passengers and a pilot.

On board the submersible were British billionaire Hamish Harding, who owned Action Aviation, Pakistani businessman Shahzada Dawood and his son Soleiman Dawood, French submarine pilot Paul Henry Nargeolet, and Stockton Rush, the founder and CEO of OceanGate Expeditions, which owned the vessel and organized the mission.

All are believed to have perished in the implosion.  

'Sadly been lost'

Earlier, tour company OceanGate, which owned the submersible, in a statement said it believes the crew members "have sadly been lost," hailing the men as "true explorers who shared a distinct spirit of adventure, and a deep passion for exploring and protecting the world’s oceans."

"The entire OceanGate family is deeply grateful for the countless men and women from multiple organisations of the international community who expedited wide-ranging resources and have worked so very hard on this mission," it said.

"We appreciate their commitment to finding these five explorers, and their days and nights of tireless work in support of our crew and their families," it added.

Asked about the possibility of recovering the crew members' remains, Mauger stressed the "incredibly unforgiving environment down there on the sea floor," but said authorities would continue to search in the debris field area. A timeline for when the operations will conclude has yet to be determined.

The admiral emphasized that officials have yet to determine when the Titan imploded, but said "there doesn't appear to be any connection between" banging noises heard beginning on Tuesday, and the debris field's location.