The U.S. Coast Guard said Thursday it found debris that may have come from the submarine that disappeared last Sunday. Experts heard by the international press indicate that they would be part of its “landing structure and rear cover”. If the possibility is confirmed by the authorities, it would mean, according to the sources, that something “very serious” has happened to the ship.

The intense search for the Titan submersible, which disappeared on Sunday with five people on board as it headed for the wreck of the Titanic in the North Atlantic, entered a critical phase on Thursday, as oxygen reserves are running out. A flotilla of planes and ships and specialized technology participate in the search for the tourist submersible.

“A debris field has been discovered in the search areas of an ROV near the Titanic. Unified Command experts are evaluating the information,” the U.S. Coast Guard statement said.

The mystery remains as to what caused the vehicle to lose contact with the surface. In one possible scenario, the Titan would have returned to the surface and was floating around, waiting to be found. According to experts, the most catastrophic scenario is that the effects of the pressure caused the submersible to implode.

Earlier, the US Coast Guard announced that a Canadian robot had reached the bottom of the ocean in the area where the submersible had gone missing. She also confirmed the commissioning of the Victor 6000 robot, which has an eight-kilometre umbilical cord and can reach more than enough depth to reach the sinking site of the Titanic on the seabed, nearly four kilometers deep.

Communication with the small submersible Titan was lost on Sunday, nearly two hours after the craft began its descent towards what remained of the famous transatlantic, at nearly 4,000 meters deep and about 600 kilometers from Terra Nova.

Who is the crew of the missing submarine?

British billionaire and aviator Hamish Harding, chairman of private jet company Action Aviation; Pakistani businessman Shahzada Dawood, vice chairman of conglomerate Engro, and his son Suleman; French diver Paul-Henri Nargeolet; and Stockton Rush, CEO of OceanGate Expeditions, the company that operates the Titan, which charges $250,000 per tourist.