At Titanic Site, the Grim Job Now Is Assessing the Submersible’s Debris

Now that the world knows what happened to the Titan, the submersible that vanished on Sunday on a dive to view the wreck of the R.M.S. Titanic, officials are turning their attention to learning how and why the vessel apparently imploded, killing everyone aboard.

The discovery on Thursday of pieces of the Titan on the ocean floor effectively ended a rescue operation that had gripped much of the world’s attention. The United States Coast Guard, which led the search, would now be “focused on documenting the scene,” Rear Adm. John Mauger said Thursday at a news conference.

On Friday, the Transportation Safety Board of Canada announced that it was launching an investigation into the disaster. The board is involved because the ship that carried the Titan to the scene and put it in the water, the M.V. Polar Prince, is Canadian.

A team of investigators will gather information and conduct interviews in coordination with other agencies, the board said.

The Titan’s fate was not known until Thursday morning in part because it took days to transport remote-operated vehicles that could reach the depth of the Titanic to the site more than two miles below the ocean surface. Once the vehicles were deployed, debris from the Titan was spotted within a few hours, in an area about 1,600 feet away from the bow of the Titanic, according to Admiral Mauger.

Experts said the remote vehicles will probably be used to continue surveying the site and to retrieve some items. But parts of the stricken submersible will probably be left on the ocean floor indefinitely, they said. It remained unclear whether any human remains were seen or could be retrieved.

“We should expect the R.O.V.s on site to identify as much as they can and also bring to the surface as much as they can,” said Jennifer K. Waters, the provost of the State University of New York Maritime College.

They would not be able to collect everything on the ocean floor, she said, but they could bring back some materials that would be useful in investigations.

If the implosion happened well above the ocean floor, fragments of the submersible may have spread across a wide area, said James G. Bellingham, a professor of exploration robotics at Johns Hopkins University. “They will have to search for Titan debris amid the Titanic debris on the bottom,” he added.

But the ocean is so deep there that “recovering anything is a huge, expensive endeavor,” said Mike Jarvis, the president of the American Salvage Association, an industry group for marine salvage workers.

The military tends to invest resources in recovering its own sunken assets, Mr. Jarvis said, but recovery efforts for private vessels like the Titan would probably be limited by the expense. He estimated that a recovery mission for the Titan might cost $250,000 a day.

The Navy sent a lifting mechanism for heavy underwater objects, called the Flyaway Deep Ocean Salvage System, to the site of the disappearance this week to help with search and recovery efforts. But it remains unclear whether, or when, the system might be used.

The Titan, a 22-foot-long tube-shaped vessel with a single porthole, was owned by OceanGate. The chief executive of the company, Stockton Rush, was piloting the submersible when it vanished.

“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,” the company said in a statement, adding that its employees were “exhausted and grieving deeply over this loss.”

OceanGate did not answer questions about recovery efforts or investigations, nor about whether any sort of data recorder — like an airplane’s black box — had been on the Titan.

The Coast Guard and the Navy did not immediately respond on Friday to questions about the future course of recovery operations.

“I know there’s a lot of questions about how, why, when this happened,” Admiral Mauger said on Thursday, adding that the authorities had those same questions. “That’s going to be, I’m sure, the focus of future review.”