Canadian investigators boarded the Titan submersible’s supply vessel after it docked in St John’s, Newfoundland, to interview crew and examine voyage data recorder logs.
On Thursday, a search-and-rescue effort ended after debris was discovered on the ocean floor, about 1,600ft from the Titanic wreck, and US Coast Guard officials announced the vessel had most likely imploded, killing the five people on board.
The Polar Prince, which launched the Titan, was escorted from international waters to a Canadian coast guard base in its home port of St John’s on Saturday morning.
For hours, about a dozen people – including investigators from the Transportation Safety Board of Canada and the Royal Canadian Mounted Police – boarded or left the ship at the Atlantic headquarters of the coast guard.
Pulling large plastic equipment cases, the transportation safety investigators were expected to look for clues that might explain what went wrong aboard the Titan, a submersible that took wealthy passengers from around the world on tours of the Titanic wreck site, 12,500ft below the surface of the Atlantic Ocean.
As the Titan lacked propulsion, the Polar Prince, a Canadian ship owned by Miawpukek Horizon Maritime Service, had tugged the Titan to its launch point and ferried the Titan’s passengers and others to their destination.
The Polar Prince remained near the launch point until the authorities ended the search and it headed to the regional coast guard headquarters. A floating platform that had been used to carry the Titan was brought in separately by a large ocean-vessel supply ship.
On Friday, the Transportation Safety Board of Canada announced the investigation and arrived in St. John’s.
Kathy Fox, the chairwoman of the safety board, said that family members of the five people who were inside the submersible when it was destroyed were among the 41 people on the ship when it sailed on June 18th.
Ms Fox said that the US Coast Guard would be in charge of recovering and examining the remains of the Titan now on the ocean floor, but that her agency would analyse any of its findings.
The Polar Prince, built in 1959 as a light icebreaker and buoy tender for the Canadian coast guard, set off from its home port of St. John’s on Sunday for the trip to the Titanic wreck site.
The ship had lain in dock several weeks before that as it was preparing for the voyage, which was delayed under inclement weather.
This article originally appeared in The New York Times.