Gabriela Pomeroy
Live reporter

A damning report published by the US Coast Guard today looked at what went wrong in June 2023, when the Titan submersible took five people on an expedition to see the Titanic shipwreck - but the sub imploded, killing all on board.

The implosion of the vessel was caused by the loss of structural integrity of its carbon fibre hull, exposing passengers to "approximately 4,930 pounds per square inch of water pressure", the report found. They died instantaneously.

The tragedy was "preventable", it said.

Investigators found “critically flawed” safety practices at the sub's owner OceanGate Expeditions, and said it used "intimidation tactics" for several years before the disaster to avoid scrutiny.

Much of the blame goes to the Chief Executive Stockton Rush, the US Coast Guard said. He was on board and also died in the disaster. The report found he "exhibited negligence that contributed to the deaths of four individuals".

The company failed to follow safety protocols. It was under financial pressure and had a "toxic workplace environment", using the firing of senior staff and the "looming threat" of being fired to dissuade employees and contractors from expressing safety concerns, the report found.

A lot of questions were answered in this investigation. But "no report can alter the heart-breaking outcome," the family of two of the victims said.

Our live updates are ending now, but you can read more details in our report here.

We've been bringing you all the key points from the US Coast Guard report today.

It all goes back to June 2023, when the OceanGate sub imploded about 90 minutes into its descent towards the wreck of the Titanic in the Atlantic Ocean.

In this special programme, Jessica Parker looks at how the search for the Titan sub unfolded - and its devastating outcome.

• You can watch the full 24-minute episode on BBC iPlayer here

As we've been reporting, a US Coast Guard report says OceanGate - the company behind the submersible that imploded - showed "a reckless disregard for safety".

Catalogue of failures: Officials said that before the tragedy, OceanGate had seriously flawed practices and did not follow established engineering protocols for safety, testing and maintenance of their submersible. The coast guard says this was the main reason for the deaths.

CEO to blame: The report was especially critical of OceanGate CEO Stockton Rush - who died on board the sub - saying he ignored vital inspections, data analyses and preventive maintenance procedures.

Mounting cash problems: The findings also reveal OceanGate was facing financial difficulties, with employees having to temporarily forgo salaries on the promise of back pay.

Weak regulation: The report also highlighted a wider issue - the lack of domestic and international oversight for manned submersibles like Titan.

The company behind the Titan sub disaster, OceanGate, says it offers its deepest condolences to the families of those who died.

In a statement, it says that after the tragedy it wound down operations and directed its resources fully towards co-operating with the coastguard's inquiry.

Image source, Reuters

The former director of engineering at OceanGate has said the engineering team was mostly made up of "young, inexperienced individuals", which led to "significant gaps in capability", according to the US Coast Guard report.

He described the Titan as similar to a "high school project".

Talking about the team's morale, the former director also told investigators that many employees were unhappy in their roles and "ill-equipped to tackle the complexities of designing a sophisticated deep-sea submersible".

Image source, PA Media

The US Coast Guard report also highlights that an earlier OceanGate prototype used "mostly off-the-shelf" components, including a modified controller for the PlayStation video game console.

That test model was retired and put on display at a museum in 2015. However, footage later shared with the BBC shows OceanGate CEO Stockton Rush inside the actual Titan sub, holding a PlayStation controller.

"We run the sub with this game controller," he says. "If you want to go forward, you press forward. If you want to go back, you press back."

Among the criticisms of how OceanGate operated are ones focusing on the manuals used by staff, including guidance for pilots on how the sub was sealed and powered.

The report found "the majority of its sections were incomplete" and many essential functions were marked as "to be determined".

Another manual - a 155-page document intended as a guide on high-risk operations - was deemed "woefully inadequate", with "only four pages" dedicated to operating at extreme depths.

The report says this is evidence of safety protocols being "either egregiously inadequate or wilfully disregarded".

More details now on the "severe financial instability" OceanGate was facing.

It had more than 30 employees at one point but "as financial strain intensified, this number dwindled".

Investigators found that CEO Stockton Rush "occasionally used his personal funds to cover operating expenses" - including advancing £1.39m ($1.85m) to the company between June 2022 and May 2023.

In 2023, employees were "asked to temporarily forgo their salaries with promises of repayment in the future".

Buried in the 327-page report are details of a 2018 meeting which investigators say was a "prime example" of OceanGate CEO Stockton Rush's "disregard for opposing views".

He clashed with his director of operations, who had just conducted an internal safety inspection of the first Titan sub and produced findings he did not approve of.

The director, who the report does not name, pointed out he'd been hired to take a "conservative approach" to safety.

Rush responded by saying the director's approach was "fundamentally opposite of the approach that I want to take". He fired the director shortly after the meeting, the report says.

"The message was clear to OceanGate's remaining senior staff that opposing views needed to be completely stifled," it adds.

Esme Stallard
Climate and science reporter

When Titan first went missing there was some confusion about whether there had been a failure and at what point that had happened.

When the sub reached a depth of 3,300m, a banging noise was heard by those in the support ship. Moments later, Wendy Rush - wife of CEO Stockton Rush, who was onboard the ship - received a text message from the sub saying it had dropped two weights. This led her to believe the dive was proceeding as expected.

But the Coast Guard has said the use of a text system is not "industry practice" and meant communications were delayed. The banging noise was in fact the sub imploding and the text had taken some time to reach the vessel on the surface.

The Coast Guard went on to say voice communication should have been used to provide real time clarity of issues, and the failure of OceanGate to implement this system was reflective of "broader cost-cutting priorities".

The team sent text messages to keep in contact with the crew on the sub's support ship, the Polar Prince, throughout its final dive.

Below is a log of the messages sent from the sub before it lost communication after one hour and a half underwater.

Nomia Iqbal
North America correspondent

Christine Dawood lost her husband, Shahzada Dawood, 48, and her son, Suleman, 19, in an instant.

A week after the disaster she spoke to the BBC in Newfoundland about what happened.

She denied cruel claims from an estranged family member that her son had been forced to go, saying she had voluntarily given him her seat. It was too painful for her to discuss any further.

Christine talked at length to me about her reaction when she heard the Titan had imploded, and what the overwhelming grief and uncertainty she was still experiencing had felt like.

Rebecca Morelle
Science editor

The submersible industry is a very responsible industry - it’s had very few failures, especially anything like this.

That’s because most people who have submersibles opt to put them through a process called certification. This is where the submersible, from its design through to its testing and operations, is assessed by an independent maritime organisation like the DNV, or the American Bureau of Shipping, or Lloyds.

Stockton Rush chose not to put his submersible through this process and therein lies the crunch.

He could choose not to put it through the process.

He said the design was too innovative, that this certification would stifle innovation - he said that in a blog post in 2019. Whereas when you speak to other submersible designers and operators, they say safety is at the centre of what we do.

Certification is voluntary, but almost everyone puts their submersibles through this process, so it’s worked up to now.

If that’s going to be the one outcome of this report – changing the regulation – I think that’s the biggest thing to ensure something like this doesn’t happen again.

A documentary from May following the investigation into the Titan disaster is available on BBC iPlayer.

Implosion: The Titanic Sub Disaster explores if it was more than a tragic accident and whether it could have been prevented, with new evidence and unprecedented access to investigators.

The programme is only available to viewers in the UK.

Nomia Iqbal
North America correspondent

Image source, Reuters

It was two years ago when we heard the astonishing news of a missing submersible in the Atlantic ocean above the Titanic wreckage.

At that stage it wasn’t exactly clear what this submersible was or what had happened. We headed over to Canada’s remote north-eastern province of Newfoundland.

What we found when we got there was silence from official institutions involved in the voyage. Clearly something had gone wrong.

After days of intense pressure, we finally heard from Horizon Maritime Services co-founder and chairman Sean Leet. His company owned and operated the Polar Prince which transported the submersible.

He was nervous and said "all protocols were followed for the mission". He clearly was not used to such scrutiny and said they were holding out hope for survivors.

For locals in the area, to have the world’s attention was of course overwhelming but they were also shocked at what had happened. They were hopeful, but many were not optimistic about anyone surviving the ocean - particularly local fisherman who understood its unforgiving nature.

The Titan sub was equipped with a real-time monitoring (RTM) system which was supposed to warn the crew about safety issues - but, the report finds, it was critically flawed. Here's why:

• Stockton Rush was said to be solely responsible for setting the warning thresholds, and OceanGate employees were unable to "explain the rationale or methodology behind" them
• There was no audible alarm for the system, as Rush "was totally against" it
• Warning signals weren't taken seriously - the report says "no dives were ever aborted due to RTM system warnings"
• The RTM system was likely not working properly, with three of its eight sensors "likely inoperable"

Esme Stallard
Climate and science reporter

The US Coast Guard report repeatedly draws attention to the financial difficulties OceanGate was facing.

From mid-2022, CEO Stockton Rush was using his personal funds to keep the company operating due to its "precarious financial state".

One former employee claimed he had a conversation with Rush in which he said OceanGate was "getting sued by all these passengers that didn't get their trip". The employee added he was not sure if any cases were brought.

The report finds that staff left because their salaries were not paid, as well as concerns over safety standards.

Their roles were filled by contractors, which meant the company was left needing to hire people who might lack "critical" knowledge, leaving it unable to address safety problems.

Today's report is highly critical of Stockton Rush, the man behind OceanGate. We profiled him in depth in 2023.

Bright, driven, born into wealth, his dream was to be the first person to reach Mars. When he realised that was unlikely to happen in his lifetime, he turned his attentions to the sea.

"I wanted to be Captain Kirk and in our lifetime, the final frontier is the ocean," he told a journalist in 2017.

He also believed it promised profits - if he could make a success of the submersible he helped design, which he directed his company OceanGate to build.

Rush had a maverick spirit that seemed to draw people in - but his soaring ambition also drew scrutiny from industry experts who warned he was cutting corners.

He was among those killed when his Titan sub imploded.

The report shines a light on OceanGate's "inconsistent" and "insufficient" training program for its pilots.

At one point, the firm aimed to qualify pilots in a single day, even if they had never operated a submersible before, a former OceanGate operations director told investigators.

He described this approach as a "huge red flag".

The report finds the company's approach to training was "inadequate and lacked the rigor necessary for ensuring safe operations".

The report is damning about Stockton Rush's role at OceanGate. It finds that he "essentially" held several roles - CEO, safety officers and pilot - which "enabled him to set operational safety parameters and then make all final decisions for Titan operations without adequate input or checks and balance".

The report finds Rush was so concerned with managing the expectations of his guests that it came at the expense of keeping everyone safe.

Each guest paid hundreds of thousands of dollars for a chance to see the Titanic wreck, and "the pressures created by the presence of VIP guests on the excursion created a 'get it done' mentality that undermined standard safety protocols".