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Rescuers in a remote area of the Atlantic Ocean raced against time on June 20 to find a missing submersible carrying five people on a mission to document the wreckage of the Titanic.The Associated Press

The Titan submersible bound for the wreckage of the 1912 Titanic disaster is now at the centre of investigations from several countries, including Canada and the U.S. The Coast Guard, which had been leading the search for debris, has confirmed that it will lead the investigation, while Canada has said its transportation safety board will look into role of the Polar Prince mothership.

The five people aboard the submersible died in what appears to have been a “catastrophic implosion,” a U.S. Coast Guard official said on Thursday. It had been missing off the coast of Newfoundland since Sunday morning, and prompted a massive search operation by U.S. and Canadian authorities.

The submersible had a 96-hour oxygen supply when it submerged on Sunday, according to an adviser for OceanGate Expeditions, predicting that oxygen would run out by Thursday morning.

What happened, who was onboard, who has led the search and who will lead the investigations? Here is what is known so far.

What is the Titan submersible?

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This photo provided by OceanGate Expeditions in June 2021 shows the company's Titan submersible.The Associated Press

The submersible, called the Titan, is designed to take five people to depths of 4,000 metres “for site survey and inspection, research and data collection, film and media production, and deep sea testing of hardware and software.” It takes two hours to descend to the Titanic, which sits at about 3,840 metres, according to the OceanGate website.

CBS News journalist David Pogue, who travelled to the Titanic aboard the Titan last year, said the vehicle uses two communication systems – text messages that go back and forth to a surface ship and safety pings that are emitted every 15 minutes to indicate that the sub is still working. Both of those systems stopped about an hour and 45 minutes after the Titan submerged on Sunday.

The submersible also had seven backup systems to return to the surface, including sandbags and lead pipes that drop off and an inflatable balloon. It had a 96-hour oxygen supply when it was put to sea on Sunday morning.

What happened to the Titan sub?

The tourist submersible started its journey Sunday morning, but lost contact with surface launch ship Polar Prince about one hour and 45 minutes into the expedition.

The Joint Rescue Coordination Centre in Halifax said it received a request from the U.S. Coast Guard shortly after 9 p.m. on Sunday to help search for a submersible that had been reported overdue about 700 kilometres south of St. John’s, N.L.

The U.S. Coast Guard is in charge of the search for the small craft, in the North Atlantic Ocean, with assistance from Canada.

Three search vessels arrived on-scene Wednesday morning, including one that has side-scanning sonar capabilities. A Canadian surveillance vessel detected underwater noises in the area on Wednesday, authorities said, though the exact location and source of the sounds was not determined. Rolling Stone reported that search teams heard “banging sounds in the area every 30 minutes.”

Captain Jamie Frederick of the First Coast Guard District said the noises were heard for a second day Wednesday, but “we don’t know what they are, to be frank.” Officials warned that analysis of the sound was inconclusive and that the noises might not have emanated from the Titan at all.

U.S. Coast Guard Rear Admiral John Mauger said “there doesn’t appear to be any relation between the noises and the location of the debris field on the sea floor,” on Thursday.

The U.S. Coast Guard said Thursday a debris field was found within the search area by a remotely operated underwater robot. Mauger said at a press conference that the debris field found is consistent with “a catastrophic implosion of the vehicle.”

What happened to Titan submersible

500km

NEWFOUNDLAND

CANADA

1

St. John’s

Boston

Wreck of

Titanic

2

New

York

U.S.

ATLANTIC

OCEAN

TIMELINE

3

June 16:

Canadian

research vessel

MV Polar Prince

sets sail

1

Titan

takes

around

two

hours to

descend

to wreck

June 18: Ship arrives

near Titanic site

2

Crew locked inside.

Hatch sealed from

outside with 17 bolts

04:00 local time:

Dive begins

3

05.45: Polar Prince

loses contact with Titan

4

4

June 19: U.S.

Coast Guard confirms

sub has been missing

for more than 24 hours

Titanic sank in

April 1912 after

hitting iceberg.

Wreck lies around

3,800m deep

Drawing not to scale

graphic news, Sources: OceanGate Expeditions; BBC

What happened to Titan submersible

500km

NEWFOUNDLAND

CANADA

1

St. John’s

Boston

Wreck of

Titanic

2

New

York

U.S.

ATLANTIC

OCEAN

TIMELINE

3

June 16:

Canadian

research vessel

MV Polar Prince

sets sail

1

Titan

takes

around

two

hours to

descend

to wreck

June 18: Ship arrives

near Titanic site

2

Crew locked inside.

Hatch sealed from

outside with 17 bolts

04:00 local time:

Dive begins

3

05.45: Polar Prince

loses contact with Titan

4

4

June 19: U.S.

Coast Guard confirms

sub has been missing

for more than 24 hours

Titanic sank in

April 1912 after

hitting iceberg.

Wreck lies around

3,800m deep

Drawing not to scale

graphic news, Sources: OceanGate Expeditions; BBC

What happened to Titan submersible

500km

NEWFOUNDLAND

CANADA

1

St. John’s

Boston

Wreck of

Titanic

2

New

York

U.S.

ATLANTIC

OCEAN

TIMELINE

3

June 16:

Canadian

research vessel

MV Polar Prince

sets sail

1

June 18: Ship arrives

near Titanic site

Titan

takes

around

two

hours to

descend

to wreck

2

Crew locked inside.

Hatch sealed from

outside with 17 bolts

04:00 local time:

Dive begins

3

05.45: Polar Prince

loses contact with Titan

4

June 19: U.S.

Coast Guard confirms

sub has been missing

for more than 24 hours

4

Titanic sank in

April 1912 after

hitting iceberg.

Wreck lies around

3,800m deep

Drawing not to scale

graphic news, Sources: OceanGate Expeditions; BBC

Who was on the Titan sub?

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This image courtesy of Dirty Dozen Productions shows Hamish Harding ahead of the 4am start of the RMS Titanic Expedition Mission 5 on the morning of June 18.AFP/Getty Images

The U.S. Coast Guard said there was one pilot and four “mission specialists” aboard the vessel, which is how OceanGate refers to its paying customers. They take turns operating sonar equipment and performing other tasks in the five-person submersible.

  • Hamish Harding: The British billionaire and chairman of Action Aviation, a United Arab Emirates-based company that sells large aircraft, was onboard, according to his stepson. Mr. Harding posted to Instagram over the weekend that he was proud to be going on OceanGate’s expedition as a “mission specialist.” He also said it was likely to be the only mission to the Titanic this year because of an extremely cold winter in Newfoundland.
  • Shahzada Dawood and his son, Suleman: Shahzada Dawood is vice chairman of one of Pakistan’s largest conglomerates, Engro Corporation, with investments in fertilizers, vehicle manufacturing, energy and digital technologies. Their family have confirmed they were on board.
  • Paul-Henri Nargeolet: The 77-year-old French explorer is director of underwater research at a company that owns the rights to the Titanic wreck. A former commander in the French Navy, he is both a deep diver and a mine sweeper. After retiring from the navy, he led the first recovery expedition to the Titanic in 1987 and was a leading authority on the wreck site.
  • Stockton Rush: The founder and CEO of the vessel’s U.S.-based operating company OceanGate was also on the submersible, according to media reports. His biography on OceanGate’s website says Rush became the youngest jet transport-rated pilot in the world in 1981 at the age of 19.

What is OceanGate Expeditions, the company operating the Titan sub?

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This 2004 photo provided by the Institute for Exploration shows the remains of a coat and boots in the mud on the sea bed near the Titanic's stern.The Associated Press

The submersible was operated by U.S.-based OceanGate Expeditions, which brings paying tourists to chronicle the deterioration of the Titanic, which struck an iceberg and sank in 1912, killing all but about 700 of the roughly 2,200 passengers and crew.

The June 18 expedition was OceanGate’s third annual voyage. An initial group of tourists in 2021 paid $100,000 to $150,000 apiece to go on the trip, but OceanGate’s website described the “mission support fee” for the 2023 expedition as $250,000 a person.

Documents show that OceanGate had been warned there might be catastrophic safety problems posed by the way the experimental vessel was developed. David Lochridge, OceanGate’s director of marine operations, said in a 2018 lawsuit that the company’s testing and certification was insufficient and would “subject passengers to potential extreme danger in an experimental submersible.”

What will happen with the investigation into what occurred?

The U.S. Coast Guard announced it will lead the investigation into what happened after the launch. The responsibility for the investigation was partially complicated by the fact that many countries were involved with the submersible – OceanGate Expeditions is based in the U.S. but the submersible was registered in the Bahamas. Meanwhile, the Titan’s mother ship, the Polar Prince, was from Canada, and the people on board the submersible were from England, Pakistan, France, and the U.S.

The Transportation Safety Board of Canada has said it will launch an investigation that will focus on the cargo vessel Polar Prince.

How the investigation will proceed is also complicated by the fact that the world of deep-sea exploration is not well-regulated. Deep-sea expeditions like those offered by OceanGate are scrutinized less than the companies that launch people into space, noted Salvatore Mercogliano, a history professor at Campbell University in North Carolina who focuses on maritime history and policy.

What is a submersible versus a submarine?

While the popular term is a submarine, the Titan vessel is called a “submersible” in marine terminology. A submarine can launch itself from a port independently, but a submersible goes down off a support ship.

With reports from Eric Andrew-Gee, Dustin Cook, Reuters, The Canadian Press and The Associated Press

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