The Titan submersible sent its final message just six seconds before it lost contact with the surface during its ill-fated dive to the Titanic, according to a US Coast Guard body probing the vessel’s implosion in June 2023, which killed all five people on board.

“dropped two wts,” the Titan’s text to its mother ship read, referring to weights the submersible could shed in hopes of returning to the surface. A lawsuit by the family of one of the victims has claimed the message, sent about 90 minutes into the vessel’s dive, was an indication the crew might have known something was wrong and were trying to abort the mission.

Instead, seconds later, the Titan was “pinged” for the last time, according to the opening presentation Monday, on the first day of a two-week hearing held by the Marine Board of Investigation tasked with reviewing the tragedy. The mother ship, the Polar Prince, then lost track of the vessel.

Days later, authorities found its wreckage resting on the floor of the North Atlantic Ocean, several hundred yards from the location of the Titanic.

Confirmation of the Titan’s final communications came early in the hearing by the Marine Board of Investigation, which also called its first witnesses: Former employees of OceanGate, the company based in Everett, Washington that developed and operated the 23,000-pound submersible, charging about $250,000 per ticket. The company has faced mounting scrutiny of its operations amid reports of safety concerns.

The Marine Board of Investigation, the highest level of inquiry by the Coast Guard, was convened within days of the submersible’s disappearance and tasked withreviewing the cause of the tragedy and offering recommendations, including about potential civil penalties and criminal prosecution.

“Over the past 15 months, our team has worked continuously in close coordination with multiple federal agencies, international partners and industry experts to uncover the facts surrounding this incident,” Jason Neubauer, the chair of the Marine Board of Investigation, said in a news conference Sunday.

“The upcoming hearings will allow us to present our findings and hear directly from key witnesses and subject matter experts in a transparent forum,” said Neubauer, adding the proceedings “are a critical step in our mission to understand the contributing factors that led to the incident and, even more importantly, the actions needed to prevent a similar occurrence.”

The submersible lost contact with its mother ship during its dive to the Titanic on June 18, 2023. When it failed to resurface, an international search and rescue mission unfolded in the remote waters several hundred miles southeast of Newfoundland, Canada.

Ultimately, authorities concluded the vessel had suffered a “catastrophic implosion” – a sudden inward collapse caused by immense pressure. Debris from the submersible was found on the sea floor several hundred yards from the Titanic, and authorities recovered “presumed human remains” believed to belong to the victims.

Stockton Rush, the founder and CEO of the vessel’s operator; businessman Shahzada Dawood and his 19-year-old son, Suleman Dawood; businessman Hamish Harding; and French diver Paul-Henri Nargeolet were all killed. Those remains were matched to the five men on board through DNA testing and analysis, the Marine Board of Investigation confirmed in its presentation Monday.

The Coast Guard previously said the hearing would include “pre-accident historical events, regulatory compliance, crew member duties and qualifications, mechanical and structural systems, emergency response and the submersible industry.”

Former engineering director says he fought with CEO

A list of witnesses includes a slate of one-time employees of OceanGate, the Everett, Washington-based company that developed and operated the 23,000-pound vessel, charging about $250,000 per ticket. The company has faced questions about its operations amid reports of safety concerns.

The first of those employees testified on Monday, including former engineering director Tony Nissen, who claimed he was fired from OceanGate in mid-2019 because he refused to sign off on an expedition around that time.

Nissen had concerns, he said, about the integrity of the Titan’s carbon fiber hull, which emerged in the aftermath of the submersible’s disappearance and implosion as a focal point of those mounting safety concerns.

Nissen described often being at odds with Rush, saying the two had “fights” that took place “behind closed doors” so other members of the engineering team wouldn’t “know that the two people on top are in solid disagreement.”

“He would fight for what he wanted and he wouldn’t give an inch, much at all,” Nissen said of Rush.

Counsel for the company are present at the hearing and are able to cross-examine witnesses but they declined to do so in Nissen’s case. At the start of Monday’s hearing, Jane Shvets, one of the company’s attorneys, offered its condolences to the families of those who died.

“There are no words to ease the loss endured by the families impacted by this tragic incident,” she said, “but we hope that this hearing will help shed light on the cause of the tragedy and prevent anything like this from happening again.”

The MBI is made up of numerous Coast Guard officials and at least two from the National Transportation Safety Board, according to a list provided by the Coast Guard. Other anticipated witnesses include regulatory officials, search and rescue specialists, experts on deep sea exploration and engineers from NASA and Boeing.

While the chief aim of the hearing is to “uncover the facts surrounding the incident,” Neubauer acknowledged the board is also tasked with identifying “misconduct or negligence by credential mariners.”

“And if there’s any detection of a criminal act, we would make a recommendation to the Department of Justice,” he said.

The Marine Board of Investigation is the highest level of Coast Guard inquiry: Approximately one MBI hearing is convened each year, Neubauer said, adding, “out of thousands of investigations conducted, less than one rise to this level.”

The hearing is being held in North Charleston, South Carolina, and is expected to take place over nine days between Monday and Friday, September 27. It is being streamed live on the Coast Guard’s YouTube page.

When the investigation is complete, the US Coast Guard and the National Transportation Safety Board will each conduct an independent analysis and complete reports, Neubauer said Sunday. He cautioned additional hearings could be held in the future, and he would not provide an estimated timeline for the conclusion of the investigation.