PORTLAND, Maine (AP) — Former employees of the company that owned an experimental submersible that imploded on its way to the wreck of the Titanic are scheduled to testify before a Coast Guard investigatory board at an upcoming hearing.

The Titan submersible imploded in the North Atlantic in June 2023, killing all five people on board and setting off a worldwide debate about the future of private undersea exploration. The U.S. Coast Guard quickly convened a high-level investigation into what happened, and that inquiry is set to reach its public hearing phase on Sept. 16.

OceanGate, the Washington state company that owned the Titan submersible, suspended operations after the implosion that killed company co-founder Stockton Rush and the others. Witnesses scheduled to appear during the upcoming hearing include Guillermo Sohnlein, who is another co-founder of OceanGate, as well as the company's former engineering director, operations director and scientific director, according to documents provided by the Coast Guard.

The public hearing “aims to uncover the facts surrounding the incident and develop recommendations to prevent similar tragedies in the future,” the Coast Guard said in a statement Friday. The ongoing Marine Board of Investigation is the highest level of marine casualty investigation conducted by the Coast Guard and is “tasked with examining the causes of the marine casualty and making recommendations to improve maritime safety,” the statement said.

The hearing is taking place in Charleston, South Carolina, and is scheduled to last two weeks. The board is expected to issue a report with evidence, conclusions and recommendations once its investigation is finished.

OceanGate's former director of administration, former finance director and other witnesses who worked for the company are also expected to testify. The witness list also includes numerous Coast Guard officials, scientists, government and industry officials and others.

The Titan became the subject of scrutiny in the undersea exploration community in part because of its unconventional design and its creator’s decision to forgo standard independent checks. The implosion killed Rush and veteran Titanic explorer Paul-Henri Nargeolet; two members of a prominent Pakistani family, Shahzada Dawood and his 19-year-old son Suleman Dawood; and British adventurer Hamish Harding.

The Titan made its final dive on June 18, 2023, losing contact with its support vessel about two hours later. When it was reported overdue, rescuers rushed ships, planes and other equipment to an area about 435 miles (700 kilometers) south of St. John’s, Newfoundland.

The search for the submersible attracted worldwide attention as it became increasingly unlikely that anyone could have survived the loss of the vessel. Wreckage of the Titan was subsequently found on the ocean floor about 300 meters (330 yards) off the bow of the Titanic, Coast Guard officials said.

The time frame for the investigation into the loss of the submersible was initially a year, but the inquiry has taken longer. The Coast Guard said in a July 2024 statement that the public hearing will “examine all aspects of the loss of the Titan, including pre-accident historical events, regulatory compliance, crewmember duties and qualifications, mechanical and structural systems, emergency response and the submersible industry.”

The Titan had been making voyages to the Titanic wreckage site going back to 2021. The company has declined to comment publicly on the Coast Guard's investigation.