A tragic loss: Remembering the brave explorers of the Titan sub

The five people who died on the Titan submersible were "true explorers", the company that operated the dive has said.

The men "shared a distinct spirit of adventure", OceanGate said in a statement.

The men died in what the US Coast Guard believes was a catastrophic implosion.

Five parts of the submersible were found on Thursday, approximately 1600ft from the bow of the Titanic wreck. It had disappeared on Sunday.

The men on board the sub included Stockton Rush, the 61-year-old CEO of OceanGate, British-Pakistani businessman Shahzada Dawood, 48, and his son Suleman, 19, and British businessman Hamish Harding, 58.

The fifth man on board, Paul-Henry Nargeolet, was a 77-year-old former French navy diver and renowned explorer.

At a news conference on Thursday, Rear Adm John Mauger of the US Coast Guard said that the debris is believed to be consistent with the Titan submersible.

It is unclear what led to the destruction of the Titan.

The disappearance of the vessel led to a massive international search involving US, Canadian, British and French efforts.

In a statement, OceanGate said it appreciated "their commitment to finding these five explorers and their days and nights of tireless work in support of our crew and their families".

Among those to pay their tributes after the announcement was Richard Garriot, the President of the US-based Explorers Club, of which Mr. Harding and Mr. Nargeolet were members.

In a statement, he said that the organization is "heartbroken" and that the memories of the men "will be a blessing and will continue to inspire us in the name of science and exploration".

Dive expert David Mearns said he lost two friends, Mr. Harding and Mr. Nargeolet, in a "most horrific way".

"Hamish Harding was a terrific character," Mr. Mearns said, adding that Mr. Nargeolet was "almost a legend really" in the field of deep-sea exploration.

The debris was located by a remote-controlled underwater search vehicle (ROV) about 1,600 feet (480m) from the wreckage of the Titanic.

Separate pieces were discovered that allowed authorities to confirm they came from the Titan, including a tail cone.

It is unclear when the implosion occurred or what may have caused it.

Rear Adm Mauger said he did not have an answer on whether the bodies of the five men on board were likely to be recovered.

"This is an incredibly unforgiving environment down there on the seafloor," he said.

ROVs will remain in the area as the investigation into what happened continues, Rear Adm Mauger added.

The search and personnel - including medical experts and technicians - will begin to be wound down.

Earlier this week, authorities said that Canadian aircraft had detected underwater sounds, which some experts speculated may have been a sign that the sub's passengers were still alive.

The Coast Guard now believes there was no connection between the noises and the location in which the Titan's debris was found on the sea floor.