Five people have died in the missing submersible, Titan, the US Coast Guard confirmed on Thursday.
The coast guard said a remotely operated vehicle (ROV) deployed from a Canadian ship had discovered the wreckage of the Titan in a debris field approximately 1 600 feet off the bow of the Titanic.
“The ROV deployed to the Canadian vessel Horizon Arctic discovered the tail section of the 21-foot submersible, Titan, that went missing Sunday,” the US Coast Guard said in a statement.
“Experts from within the unified command are evaluating the imagery and debris while continuing the ROV’s search efforts near the Titanic to locate additional portions of the Titan.”
The coast guard said the five people aboard the vessel had died in what appears to have been a “catastrophic implosion”. The vessel was lost during its voyage to the century-old Titanic wreck that lies four kilometres below the surface of the ocean.
OceanGate Expeditions, the US company that operated the submersible, said in a statement that "these men were true explorers who shared a distinct spirit of adventure, and a deep passion for exploring and protecting the world's oceans.
"Our hearts are with these five souls and every member of their families during this tragic time."
US Coast Guard Rear Admiral John Mauger said at a media briefing that the debris found was “consistent with a catastrophic implosion of the vehicle”.
According to Reuters, the five people aboard included the British billionaire and explorer Hamish Harding, 58; Pakistani-born business magnate Shahzada Dawood, 48, and his 19-year-old son, Suleman, both British citizens; French oceanographer and Titanic expert Paul-Henri Nargeolet, 77, who had visited the wreck dozens of times; and Stockton Rush, the American founder and chief executive of OceanGate, who was piloting the submersible.
Rescue teams from several countries spent the whole of this week searching thousands of square miles of open seas with planes and ships for any sign of the 6.7-metre Titan. The search covered more than 16 000 square km of ocean.