(NEXSTAR) – Coast Guard officials briefed the media Thursday following the discovery of debris determined to belong to the Titan submersible, which lost contact with its support crew less than two hours after embarking on its dive to the wreckage of the Titanic on Sunday.

The vessel, officials said, suffered a “catastrophic implosion” during its journey to the wreckage, the cause of which is still under investigation.

On Thursday afternoon, just hours after experts estimated the oxygen on the Titan would have run out for any surviving passengers, Coast Guard officials confirmed that at least five pieces of the vessel had been found during search-and-rescue efforts.

The pieces, found approximately 1,600 feet from the bow of the Titanic, included the nose cone, pieces of the hull, and the front and aft end bells, according to Paul Hanken, an undersea expert who spoke at Thursday afternoon’s news conference.

“That was the first indication there was a catastrophic event,” Hanken said.

Rear Admiral John W. Mauger of the U.S. Coast Guard, speaking to the press Thursday, could not say when exactly the Titan suffered the implosion but indicated that sonar equipment used by search teams did not pick up the sound of anything “catastrophic” since they were first used in the rescue efforts.

“Right now, it is too early to tell,” Mauger said, responding to a question on whether he believed the implosion regarding the time of the implosion.

“We’ve had sonar buoys in the water, nearly continuously, and have not detected any catastrophic events when those sonar buoys have been in the water.”

Mauger added that the buoys had been working to detect undersea noises since at least Monday afternoon.

When asked if time was a factor in a possible recovery of the Titan and its crew, Mauger again said the Coast Guard’s listening devices “did not hear any signs of catastrophic failure” after they were put into the water, suggesting the implosion occurred prior to the deployment of the buoys.

Coast Guard officials said they would continue the search as part of their investigation.

OceanGate, the company that operated the submersible, released a statement shortly before the press conference saying the crew of the Titan “have sadly been lost.”

“These men were true explorers who shared a distinct spirit of adventure, and a deep passion for exploring and protecting the world’s oceans,” the company wrote of its CEO and submersible pilot Stockton Rush and passengers Shahzada Dawood, Suleman Dawood, Hamish Harding and Paul-Henri Nargeolet. “Our hearts are with these five souls and every member of their families during this tragic time.”