Pieces from the destroyed Titan submersible were brought to land on Wednesday, as Canadian and US investigators probe the cause behind the fatal implosion.

All five people on board the submersible, which was traveling to the wreck of the Titanic, were killed when their vessel imploded in the North Atlantic.

The US Coast Guard said experts recovered "presumed human remains" from the wreckage.

"United States medical professionals will conduct a formal analysis of presumed human remains that have been carefully recovered," the agency said in a statement.

What is the latest?

The twisted and shattered remains of the Titan submersible were brought into port at St. John's harbor in the eastern Canadian province of Newfoundland. 

Images from the scene showed a crane unloading what appeared to be the sub's nose. Other fragments and pieces of debris were partly visible from underneath white tarps.

It was not immediately clear where the debris is headed. 

Several government agencies in the United States and Canada have launched an investigation into why the vessel imploded, hoping the fragments of the Titan will help shed light on what went wrong.

The debris was uncovered from the seabed, located around 1,600 feet (488 meters) away from the wreck of the Titanic and at a depth of more than 12,500 feet.

A robotic diving vehicle known as an ROV searched the ocean floor for pieces of the destroyed submersible.

"Our team has successfully completed off-shore operations, but is still on mission and will be in the process of demobilization from the Horizon Arctic this morning," Pelagic Research, which operates the ROV, said in a statement.

The company did not comment on the status of the investigations, citing confidentiality reasons.

Questions remain as families mourn

The search for the missing Titan and its crew garnered international attention last week after news emerged that the team had gone missing.

The sub was operated by OceanGate Expeditions, a company offering submersible tours of the Titanic wreck. The operator charged $250,000 per person to participate in the voyage.

On board the vessel were OceanGate Expeditions CEO Stockton Rush; British billionaire Hamish Harding, French oceanographer Paul-Henri Nargeolet, as well as Pakistani-born businessman Shahzada Dawood and his 19-year-old son, Suleman.

The Titan set off on June 18 and is believed to have imploded during its descent. When the submersible's mother ship, the Polar Prince, lost contact with the sub, a major multinational search and rescue mission was launched.

The search ended on June 22 after the debris was uncovered, with the US Coast Guard saying the Titan suffered a "catastrophic implosion."

The deadly incident has sparked questions and criticism over a lack of regulation with private undersea explorations.

zc, rs/nm (AP, Reuters, AFP)