The crew on board the Titan sub knew that it was about to implode, $50M lawsuit says

• The family of a French explorer killed on the Titan sub is suing OceanGate for over $50 million.
• Paul-Henri Nargeolet died alongside four other people last year when the sub imploded.

The crew of the ill-fated Titan submersible knew that the vehicle was about to implode as it descended and suffered "terror and mental anguish," according to a new lawsuit.

The allegation was made by the family of French explorer, Paul-Henri Nargeolet, who was killed on the Titan sub last year. They are suing OceanGate, the estate of its CEO, Stockton Rush, and others for more than $50 million.

OceanGate's ill-fated trip to the Titanic shipwreck on June 18, 2023, killed all five people on board. The sub is thought to have imploded within hours of its descent, raising concerns about OceanGate's approach to innovation and safety.

The lawsuit said the implosion was the result of the "carelessness, recklessness and negligence" of Oceangate, Rush, and others.

According to the lawsuit, the Titan sub "dropped weights" a little over an hour into its dive, indicating the team had attempted to terminate the expedition.

The lawsuit goes on to say: "The crew may well have heard the carbon fiber's crackling noise grow more intense as the weight of the water pressed on Titan's hull."

"The crew lost communications and perhaps power as well. By experts' reckoning, they would have continued to descend, in full knowledge of the vessel's irreversible failures, experiencing terror and mental anguish prior to the Titan ultimately imploding."

Nargeolet, nicknamed "Mr. Titanic," was hired to help OceanGate, during the Titan's submersible's trip to the Titanic. But the wrongful-death suit claims that he was misled about the trip.

"Mr. Rush confessed to a 'mission specialist' on one Titanic voyage that he had 'gotten the carbon fiber used to make the Titan at a big discount from Boeing because it was past its shelf life for use in airplanes,'" according to the lawsuit, which was filed on Tuesday in King County, Washington.

Nargeolet had participated in 37 dives to the wreckage of the Titanic, which the court filing said is the most of any diver in the world. His dives included part of the first expedition to visit the Titanic in 1987, shortly after its location was discovered.

The court documents described Rush as an "eccentric and self-styled 'innovator" who had an "obsession with being remembered for 'innovation' alongside such luminaries as Steve Jobs and Elon Musk."

They also referred to instances like the firing of former employee David Lockridge after he raised concerns about the submersible's safety and the fact that the Titan deviated from the industry standard of using titanium for its hull.

"TITAN was and remains the only submersible ever produced with a carbon-fiber hull," said the suit.

Chief engineer Tony Nissen was specifically called out for allegedly hiring a "2017 graduate and having six or fewer years' of relevant work experience" as the lead electrical engineer on the project.

OceanGate has suspended all exploration and commercial operations since the tragedy.

The King County Superior Court Clerk's office has set the first trial date to August 2025.

Legal representatives handling the case did not reply immediately to Business Insider's request for comment.