The co-founder of Titanic tourist company OceanGate is said to have ignored a "really loud bang" on the doomed vessel Titan before he and four others died.
Stockton Rush, OceanGate's CEO, was onboard when the Titan submersible suddenly went missing in June, before its ruined debris was found close to the Titanic.
He told an episode of BBC's The Travel Show a passenger had heard a concerning sound while the vessel was on the ocean surface.
It was "not a soothing sound", he said on the 2022 show, but said that “almost every deep-sea sub makes a noise at some point”.
Questions remain over the safety of Titan and Rush's approach to safety after the likely "catastrophic implosion" it suffered.
Kate Winslet recalls 'weird' sex scenes with Leo DiCaprio in front of husbandOn the show, Rush told the tourists he wanted them all to be "fully informed" about the dangers they were facing.
He said: "This is an experimental sub, this is a dangerous environment.”
Whistleblowers have said glue leaked from the seams holding the ballast bags together, while experts questioned the design of the submersible's hull.
In 2021, Rush said in an interview: "I have broken some rules to make this. The carbon fibre and titanium... there is a rule that you don’t do that... Well, I did."
Former consultant for OceanGate Rob McCallum told Rush Titan was a risk until it was certified by an independent body.
The Titan operated in international waters, far from the reach of many laws of the United States or other nations. It wasn’t registered as a US vessel or with international agencies that regulate safety, nor was it classified by a maritime industry group that sets standards on matters such as hull construction.
"I think you are potentially placing yourself and your clients in a dangerous dynamic," McCallum told Rush.
Rush told McCallum that he took the doubts over Titan's safety as a "serious personal insult."
"We have heard the baseless cries of 'you are going to kill someone' way too often," he wrote.
In a re-surfaced podcast with CBS, Rush talked about the submersible vessel he claims safety is a "pure waste".
First ever full-sized Titanic wreck 3D scans show it resting on bottom of oceanIn an interview in November 2022, he said: "You know, at some point, safety is just a pure waste. I mean, if you just want to be safe, don't get out of bed, don't get in your car, don't do anything."
Guillermo Sohnlein, co-founder of OceanGate Expeditions, told BBC Radio 4's Today programme that Titan had undergone 14 years of "rigorous" and "robust" checks during development.