(NEW YORK) — A submersible carrying five people has gone missing while on a tour of the underwater wreckage of the Titanic off the coast of Newfoundland, Canada.

The deep-sea vessel, operated by OceanGate Expeditions, lost contact about an hour and 45 minutes after submerging on Sunday morning with a 96-hour oxygen supply. The United States Coast Guard, in coordination with the Canadian Coast Guard and the Canadian Armed Forces, immediately launched a search and rescue operation for the 21-foot sealed craft, named Titan.

Here’s how the news is developing. All times Eastern:

Jun 21, 6:57 AM EDT
‘Banging’ picked up by sonar in search area, source says

A source familiar confirmed to ABC News that there were reports of “banging” that were picked up by sonar in the search area on Tuesday morning, but nothing has yet been found.

The U.S. Coast Guard had said early Wednesday that an aircraft with sonar capability “detected underwater noises in the search area,” but remotely operated vehicles were unable to find the origin of the sound.

Jun 21, 6:34 AM EDT
Titanic mapping company ‘fully mobilized’ to help

Magellan, an international exploration company that digitally mapped the Titanic wreckage last year, said Wednesday that it is “ready to support” the search for the missing submersible and is “fully mobilized to help.”

The U.K.-based company told ABC News that it was contacted by the submersible’s operator, OceanGate Expeditions, early Monday and “immediately offered our knowledge of the specific site and also our expertise operating at depth considerably in advance of what is required for this incident.”

“We have been working full-time with U.K. and U.S. agencies to secure the necessary air support to move our specialist equipment and support crew,” Magellan said in a statement.

When asked for comment about media reports that U.S. authorities have failed to give Magellan the necessary permits to participate in the search, the company told ABC News it “does not not wish to comment on any specific media report.”

Jun 21, 12:34 AM EDT
USCG: Canadian aircraft detected ‘underwater noises’ but search ‘yielded negative results’

“Canadian P-3 aircraft detected underwater noises in the search area,” the U.S. Coast Guard tweeted early Wednesday morning. “As a result, ROV operations were relocated in an attempt to explore the origin of the noises. Those ROV searches have yielded negative results but continue.”

The data from the P-3 has been shared with U.S. Navy experts for further analysis, the Coast Guard added.

Jun 21, 12:34 AM EDT
Lawsuit alleged flaws with Titanic sub now missing

A former employee of OceanGate alleged in a 2018 counterclaim lawsuit that he was fired for raising concerns about quality control and testing of potential flaws in the same experimental submersible that went missing this week.

David Lochridge, an engineer and submarine pilot, claimed in his counterclaim against OceanGate that he was hired in 2015 by the Everett, Washington, company to ensure the safety of all crew and clients during the submersible and surface operations of the vessel called Titan. But when he expressed concerns about the design and testing of the minisub’s hull, he said he was terminated by the company.

OceanGate had initially sued Lochridge alleging, among other things, breach of contract, fraud and misappropriation of trade secrets — all claims he denied.

In its lawsuit, OceanGate accused Lochridge of breaching his contract by discussing the company’s confidential information with the Occupational Health and Safety Administration “when he filed a false report claiming that he was discharged in retaliation for being a whistleblower.”

Jun 20, 10:15 PM EDT
Latest Coast Guard bulletin spells out timeline for missing sub search

The U.S. Coast Guard sent out its latest release Tuesday night on the search for the missing submersible at the Titanic crash site.

According to the latest release:

Sunday, June 18, 8 a.m. ET: Submersible launches, supposed to resurface at 3 p.m., but an hour and 45 minutes into the dive, it loses contact.

Sunday, June 18, 5:40 p.m. ET: Coast Guard receives report of overdue submersible.

Monday, June 19: Coast Guard Air Station Elizabeth City, North Carolina, and C-130 Hercules aircraft, as well as a Canadian P8 aircraft equipped with underwater sonar capability, search for the missing submersible, according to a previous release.

Tuesday, June 20, 7 a.m. ET: Bahamian research vessel Deep Energy arrives.

Tuesday, June 20, 4 p.m. ET: C-130 crew from Air National Guard 106th arrives.

Jun 20, 8:33 PM EDT
Experts expressed Titan safety concerns in 2018 letter

Members of a committee specializing in submersibles expressed “unanimous concern regarding the development” of Titan in a 2018 letter addressed to OceanGate CEO Stockton Rush, who is one of the passengers aboard the missing vessel.

The letter was obtained by The New York Times and was later authenticated by ABC News.

The letter warned of possible “catastrophic” problems with Titan’s development that could have “serious consequences for everyone in the industry.” The letter goes on to say that OceanGate’s safety claims were “misleading to the public” and insisted Titan be reviewed by a third-party organization.

The letter, which was addressed from the Marine Technology Society, was never approved to be sent to OceanGate though was quickly leaked to its CEO, according to committee chair William Kohnen.

“The letter did represent in 2018 the consensus by many people in the industry that they were not considering following the standard safety protocols and designs that the industry uses,” Kohnen told ABC News.

Though he wishes it was not leaked at the time, nor now to The New York Times, Kohnen said he stands by the letter and its warnings.

“The company had indicated that their state of innovation was beyond, beyond what was allowable within the regulatory standards we have today and that they would proceed without certification,” Kohnen said. “That worried a number of people in the industry.”

Kohnen acknowledged that OceanGate did “heed” some of the comments made in the 2018 letter.

-ABC News’ Amanda Maile and Victor Ordoñe​z

Jun 20, 6:02 PM EDT
NASA weighs in on missing submersible

NASA released a statement Tuesday on the Titan, saying it remains “hopeful the crew will be found unharmed.”

“NASA’s Marshall Space Flight Center had a Space Act Agreement with OceanGate, and consulted on materials and manufacturing processes for the submersible. NASA did not conduct testing and manufacturing via its workforce or facilities,” the agency said.

-ABC News’ Gina Sunseri

Jun 20, 6:17 PM EDT
Search teams have covered 7,600 square miles

Search and rescue teams have now covered 7,600 square miles — an area bigger than the state of Connecticut — as they scour the ocean for the missing submersible, Coast Guard officials said.

A grid depicting the expanding search area is expected Tuesday night, according to a public information affairs lieutenant for the First District of the U.S. Coast Guard.

-ABC News’ Miles Cohen

Jun 20, 3:09 PM EDT
US Navy sending salvage experts, equipment to help with submersible

The U.S. Navy said it’s sending to the search site experts and equipment “designed to provide reliable deep ocean lifting capacity for the recovery of large, bulky, and heavy undersea objects.”

The equipment, which can lift up to 60,000 pounds, and the experts will arrive in Canada Tuesday night, the Navy said.

National Security Council spokesperson John Kirby said earlier Tuesday that the Navy was”on standby” to help with the search for the missing submersible, because the Navy has “some deep-water capabilities that the Coast Guard wouldn’t necessarily have.”

President Joe Biden is “watching events closely,” Kirby said, adding that Biden and the White House offer their thoughts “to the crew onboard, as well as to the — what is no doubt — worried family members back on shore.”

Jun 20, 1:24 PM EDT
3 Air Force C-17’s transporting equipment to Newfoundland

Three U.S. Air Force C-17 cargo aircraft will be transporting commercial equipment from Buffalo, New York, to Newfoundland, Canada, to help with the search efforts, according to a U.S. official.

-ABC News’ Luis Martinez

Jun 20, 1:16 PM EDT
Search area larger than Connecticut, about 41 hours of oxygen left

Efforts to locate the missing submersible are ongoing, and the “complex” search covers an area larger than the state of Connecticut, Coast Guard Capt. Jamie Frederick said at a news conference Tuesday.

Crews are scouring the ocean 900 miles east of Cape Cod and 400 miles south of St. John’s, Canada, he said.

The missing five-person crew on the submersible has about 41 hours of oxygen left, Frederick noted.

“We will do everything in our power to effect a rescue,” Frederick said.

“We have a group of our nation’s best experts,” he said, and once the sub is located, “those experts will be looking at what the next course of action is” to rescue the crew members.

“Our thoughts and prayers are with the crew and their families and their loved ones,” Frederick added.

Jun 20, 12:58 PM EDT
Former ABC News correspondent recounts moment his sub was trapped in Titanic’s propeller

In 2000, Dr. Michael Guillen, then an ABC News correspondent, was filming from the wreck of the Titanic when his vessel became trapped in the propeller.

“When we collided with the propeller, and I started seeing those big chunks of metal raining down on us … the first reaction I had was, ‘This can’t be happening,"” he recalled to ABC News on Tuesday.

“We got caught by this underwater turn and just drove us right into the blades,” Guillen said.

“This voice came into my head and said, you know, ‘This is how it’s going to end for you,"” he recalled. “I’ll never forget those words.”

“I’m very aware of what these poor souls on board the ship the Titan are experiencing,” he said. “I am just heartbroken about it.”

Jun 20, 11:35 AM EDT
French sending assistance

At the request of French President Emmanuel Macron, a French ship named Atalante is diverting to the area of the missing submissive and should reach the area Wednesday night.

The ship has an exploration robot that can dive up to 4,000 meters, according to a spokesman for France’s Ifremer Institute.

Jun 20, 9:04 AM EDT
‘It’s a race against time’

Per Wimmer, an explorer and global financier, told ABC News he was “shocked” and “horrified” to hear of the missing submersible.

“It felt very personal. … I’ve been wanting to go down to the Titanic for more than a decade,” Wimmer said.

He estimated that there’s been between 150 and 200 missions to the Titanic.

There “are very, very few submersibles in the whole world that can go down to the depth of Titanic, which sits at 3,800 meters, or about 12,000 feet,” Wimmer said. “It’s very deep — most submersibles can go down to about 1,000 meters.”

“It’s a race against time, because there’s only 96 hours of oxygen on board. And after that, if you haven’t reached the surface, you starve of oxygen,” he said.

“Our best hope at the moment is that the safety mechanism will be activated,” he said. “It is supposed to be able to float to the surface, little by little, and then they can open the hatch and hopefully get out again. That is the only hope we have, because you do not have enough time to get another submersible that can go that deep.”

Jun 20, 8:19 AM EDT
What to know about the 5 people aboard the missing sub

Renowned explorers and a father-son duo were among the five people aboard a submersible that disappeared in the Atlantic Ocean on Sunday while touring the Titanic wreckage, ABC News has learned.

ABC News has confirmed and identified four of those on aboard as Hamish Harding, a British businessman, pilot and space tourist; Paul-Henri Nargeolet, a French diver and Titanic expert; Shahzada Dawood, a Pakistani businessman, and his son Suleman Dawood.

Jun 20, 7:48 AM EDT
US Coast Guard commander talks search for missing sub

The United States Coast Guard commander leading the search for a missing submersible off the coast of Newfoundland, Canada, said Tuesday morning that crews in multiple aircraft have flown over an area of the Atlantic Ocean “roughly about the size of Connecticut” while “looking for any signs of surfacing.”

“As we continue on with the search, we’re expanding our capabilities to be able to search under the water as well,” Rear Adm. John Mauger, commander of the First Coast Guard District, told ABC News’ Robin Roberts during an interview on Good Morning America.

A commercial vessel with remotely operated vehicles is now on scene that will allow rescuers to search underwater, according to Mauger.

“This is a complex case,” he added. “The Coast Guard doesn’t have all the resources to be able to affect this kind of rescue, although this is an area that’s within our search zone.”

In many cases, Mauger said, the Coast Guard’s role is to coordinate all of the assets and technical expertise that can be used in a search, in addition to operating aircraft or ships when necessary.

“In this particular case, we’ve established a unified command with the United States Navy, with the Canadian Armed Forces, with the Canadian Coast Guard and with the private operator OceanGate Expeditions to make sure that we understand what’s needed and deploy all available equipment to the scene that could be used to locate this submersible, whether it’s on the surface or down beneath the surface,” he said.

Crews have been working “around the clock” to locate the deep-sea vessel since it lost contact with its operator on Sunday morning, according to Mauger.

In the last 24 hours, a Canadian aircraft has been dropping sonar buoys into the water that can pick up sound the submersible may be emitting. Vessels that have the capability to listen with their own sonar equipment are also on scene, according to Mauger.

“If they are making sound, that’s certainly one of the ways that we’re going to use to locate them,” he said.

Jun 20, 6:18 AM EDT
Missing sub is believed to be deeper than NATO rescue capability

A tourist submersible that disappeared in the Atlantic Ocean on Sunday is believed to be at depths that greatly exceed the capabilities of the NATO Submarine Rescue System (NSRS), according to a spokesperson for the United Kingdom’s Ministry of Defense.

“As the host nation for NATO’s multinational submarine rescue capability, we continue to monitor the incident in the North Atlantic and will guide and assist in any response activity as appropriate,” the spokesperson told ABC News in a statement on Tuesday.

The U.K. has not been approached to offer assistance in the ongoing search for the deep-sea vessel off the coast of Newfoundland, Canada, according to the spokesperson.

Initial reports indicate that the depths of water involved greatly exceed that which the NSRS team can safely operate — 610 meters for the NSRS submersible and 1,000 meters for the NSRS remotely operated vehicle, according to the spokesperson.

The NSRS is based at the home of the U.K. Royal Navy Submarine Service in HM Naval Base Clyde, the U.K. Royal Navy’s headquarters in Scotland. Introduced in 2006, the tri-national capability team can respond to a stricken submarine in rescuable water which is capable of mating with the NSRS submarine rescue vehicle, according to the spokesperson.

Jun 20, 5:03 AM EDT
Former Navy sub captain on rescue options

Rescuers racing against the clock to save the five people trapped in a tourist submersible nearly two miles deep in the Atlantic Ocean are facing major obstacles that could make saving the people onboard extremely difficult, according to a former U.S. Navy submarine commander.

Retired Capt. David Marquet told ABC News on Monday that this type of rescue operation is complicated because there aren’t nearby U.S. or Canadian underwater vessels that can go as deep as the Titanic wreckage, which sits 13,400 feet below the ocean’s surface. Also, the ocean is pitch black at that depth.

“The odds are against them,” Marquet said. “There’s a ship in Boston that has this ability to either lower cable and connect to it or have a claw. It’s still a thousand miles away.”

Even if a vessel was able to locate the submersible and lower a cable, it’s extremely difficult to safely navigate the waters and attach it, according to Marquet.

“You’ve got to get it exactly right,” he told ABC News. “It’s sort of like … getting one of those toys out of those arcade machines. In general, you miss.”

Rescuers do have one advantage, Marquet said, as weather conditions off the coast of Newfoundland are not rough and will not disturb any boat or vessel there.

Marquet added that if the five people aboard are still alive, they would be asked to sleep to conserve their oxygen.

“We would put the vast majority of the crew to sleep because that’s when you’re using the least amount of oxygen and you’re expelling the least amount of carbon dioxide,” he said.

Jun 20, 4:27 AM EDT
What to know about the missing sub

A submersible on a tour of the Titanic wreckage was reported overdue by its operator OceanGate Expeditions on Sunday, prompting the United States Coast Guard to launch a search and rescue effort for the 22-foot, 23,000-pound vessel.

Designed with life support to sustain five crew members for 96 hours, the submersible would need to be rescued in three days to save its five passengers, according to the Coast Guard.

Stockton Rush founded Washington-based OceanGate in 2009 to make deep-sea exploration more accessible to scientists and tourists. Fourteen years, more than 200 dives and three submersible designs later, the company now finds itself in a desperate search to recover the submersible carrying five people aboard that’s gone missing off the coast of Newfoundland, Canada.

OceanGate confirmed Monday it had lost contact with a submersible, saying in a statement: “We are exploring and mobilizing all options to bring the crew back safely. Our entire focus is on the crewmembers in the submersible and their families. We are working toward the safe return of the crewmembers.”

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