The wife of the OceanGate chief executive asked “what was that bang?” as she unknowingly listened to the moment the Titan submersible imploded, footage has revealed.
Five people died when the craft catastrophically failed about 90 minutes into a trip to the ocean bed to view the wreck of the Titanic in June 2023.
On board the tragic voyage were Oceangate's CEO Stockton Rush, British explorer Hamish Harding, veteran French diver Paul Henri Nargeolet, the British-Pakistani businessman Shahzada Dawood and his 19-year-old son Suleman.
Footage showing the moment the sub imploded was obtained by the BBC for a new documentary Implosion: The Titanic Sub Disaster.
Provided by the US Coast Guard, it shows Wendy Rush, the wife of Mr Rush, hearing the sound of the implosion while watching on from the sub's support ship.
The vessel was with the sub while it was diving in the Atlantic Ocean.
The video shows Mrs Rush, who was a director of Oceangate with her husband, sitting in front of a computer that was used to send and receive text messages from Titan.
Chillingly, she turns and asked a colleague "what was that bang?" when she hears the noise, not realising she had just heard the moment of her husband’s death.
All five people on board Titan died instantly.
The noise is described by investigators from the coast guard as sounding like a door slamming.
Within moments Mrs Rush then receives a text message from the sub saying it had dropped two weights, which seems to have led her to mistakenly think the dive was proceeding as expected.
However, the text message, which is thought was sent just before the sub failed, took longer to reach the ship than the sound of the implosion.
The documentary also reveals the carbon fibre used to build the submersible started to break apart a year before the fatal dive.
Prior to the fatal dive, warnings had been raised by deep sea experts and some former Oceangate employees about Titan's design. One described the disaster as "inevitable".
USCG investigators believe that the carbon fibre layers of the hull started to break apart during a previous dive to the Titanic, a year before the disaster - the 80th dive that Titan had made.
Passengers on board reported hearing a loud bang as the sub made its way back to the surface. They said that at the time Mr Rush said that this noise was the sub shifting in its frame.
Titan took passengers on three more dives in the summer of 2022 - two to the Titanic and one to a nearby reef, before it failed on its next deep dive, in June 2023.
The video has been presented as evidence to the USCG Marine Board of Investigation, which has spent the last two years looking into the sub's implosion.
The US Coast Guard is due to publish a final report into the investigation later this year.
In a statement Oceangate told the BBC: "We again offer our deepest condolences to the families of those who died on June 18, 2023, and to all those impacted by the tragic accident.”
"Since the tragedy occurred, Oceangate permanently wound down its operations and focused its resources on fully cooperating with the investigations. It would be inappropriate to respond further while we await the agencies' reports."
