Missing Titanic Sub Passengers 'Have Sadly Been Lost,' Company Behind Voyage Says

Five people who were on a sub that went missing during a voyage to the wreckage of the Titanic are believed to be dead, the company that planned the trip said in a statement to CBS News. The announcement was made after a deep-sea robot found a "debris field" while searching for the sub, the U.S. Coast Guard said Thursday.

Sub passenger Paul-Henri Nargeolet's publicist, Mathieu Johann, confirmed to CBS News that fragments of the debris are from the sub. BBC News reported the debris includes "a landing frame and a rear cover from the submersible."

The Coast Guard said Thursday morning that a robot from a Canadian vessel had reached the sea floor near the Titanic to look for the sub. Experts were evaluating the discovery by the ROV, or remotely operated vehicle. Officials were expected to discuss the findings during a news conference Thursday afternoon.

"A debris field was discovered within the search area by an ROV near the Titanic," officials said.

Another robot from a French vessel was also launched into the water Thursday amid a massive international search effort for the lost 21-foot sub Titan.

In addition to the underwater robots, search planes and ships have been deployed to the northern Atlantic Ocean in the hopes of finding the sub approximately 900 nautical miles from Cape Cod, Massachusetts. The Coast Guard said Wednesday the search area was about twice the size of Connecticut. 

The sub launched into the Atlantic from a Canadian research vessel Sunday morning, and the ship lost contact with the Titan an hour and 45 minutes into the dive.

Officials previously said the sub had a limited amount of oxygen on board that could have lasted 96 hours, or roughly until Thursday morning.

On Wednesday, Coast Guard Capt. Jamie Frederick said the amount of remaining oxygen was "a dialogue that's happening" but not the only detail being considered in continuing the search.

The co-founder of the company that owns the sub, OceanGate, said Thursday was "a critical day" in the search. In a statement on Facebook, Guillermo Sohnlein said the group may have extended their life support supplies by "relaxing as much as possible."

"I firmly believe that the time window available for their rescue is longer than what most people think," Sohnlein said.