On April 10, 1912, the Titanic launched its maiden voyage from Southampton, England, to New York. The massive ship was known for its luxurious accommodations.

On April 14, the ship made contact with an iceberg and the blow was fatal — early in the morning on April 15, the ship began sinking, leading to the deaths of more than 1,500 passengers and crew members who were on board.

The boat has been the subject of cultural interest since it sank over 100 years ago. James Cameron’s 1997 movie “Titanic” is just one example of the ways the Titanic has cultivated interest since its sinking. The Titanic sits at the bottom of the ocean floor in the deep sea where there’s intense pressure, cold temperatures and no light.

To see the remains of the Titanic, a submersible called Titan dove down into the ocean on Sunday. The U.S. Coast Guard said the crew on the submersible lost contact with the Canadian research ship Polar Prince about an hour and 45 minutes after the dive. 

On Thursday, Rear Adm. John Mauger of the Coast Guard said the debris found “is consistent with the catastrophic loss of the pressure chamber,” according to Deseret News. This means the Coast Guard believes the sub imploded and the five passengers on board are believed to be dead.

Here’s a deeper look at the Titan, the search and rescue efforts that were conducted and what the conditions of the sub were.

Missing Titanic submersible updates: Passengers and pilot presumed dead

Who are the Titan passengers?

There are five people aboard the Titan — Stockton Rush, CEO of OceanGate; Hamish Harding, a British aviator; Shahzada Dawood, a British Pakistani businessman; Suleman Dawood, son of Shahzada Dawood; and Paul-Henry Nargeolet, director of Underwater Research for E/M Group and RMS Titanic Inc.

According to The New York Times, “The dozens of dives Mr. Nargeolet has made to the wreck site include previous OceanGate expeditions on the Titan, the missing submersible.” The first time he made the dive to the Titanic was in July 1987. 

What is the Titan?

The Guardian described the Titan as “a research and survey submersible that can carry five people, usually a pilot and four ‘mission specialists’ who can include archaeologists, marine biologists or anyone who can afford the experience as a tourist.” It weighs 23,000 pounds and has a 96-hour system of bottled oxygen. 

The Titanic is on the ocean floor around 12,500 feet below sea level, according to The Guardian. The submersible can go down to the depth of 13,120 feet. 

The submersible is around 22 feet long and travels at about 3 knots, according to The Conversation. Guests on board paid $250,000 for the trip. 

Rush is the creator of the Titan, according to The Guardian.

What’s the difference between a submersible and a submarine?

The Titan is a submersible which has less power than a submarine. ABC 7 News said, “A submarine has enough power to leave port and come back to port under its own power.” On the other hand, a submersible launches from a mother ship, has less power than a submarine and needs a mother ship for support. 

What’s it like inside the Titan?

“CBS News Sunday Morning” correspondent David Pogue, who went on the OceanGate Titan in November, told NPR that being inside the submersible was like being in a “minivan without seats.” Inside, there are computer screens, as well as a porthole that looks out into the ocean. 

Pogue said to NPR, “There really is no safety gear in there except for a fire extinguisher and fire masks, which we practiced putting on and taking off. That’s pretty much it, because there’s not much you can do if something goes wrong.” He said if something goes wrong, the sub has seven different ways to return to the surface. 

The hatch of the submersible is closed by 17 bolts, according to The Boston Globe. The submersible communicates by exchanging text messages using an ultra-short baseline acoustic system and is supposed to communicate with the mother ship — the Polar Prince — every 15 minutes. CNN correspondent Gabe Cohen, who sat inside the Titan in 2018, said, according to ABC 7, “You have to sit inside of it, shoes off.”

Rush, CEO of OceanGate, previously told The Guardian that the submersible was custom-made for seeing the Titanic. “We had to make our own sub. So our sub weighs about half as much as any other deep diving sub, or research sub, that’s been down there. And it because it’s smaller and lighter, it’s much more manoeuvrable. And so we can get very close.”

About the space inside Titan, The Guardian reported Rush had compared it earlier to what it’s like to be in an airplane. 

The sub is controlled by a video game controller. Vox reported, “Even the U.S. Navy uses Xbox controllers to operate the photonic scopes that replaced periscopes on submarines.” At the depth the Titan goes, they are unable to use GPS.

Retired Navy Capt. David Marquet told CNN what the possible conditions are for those in the submersible, “They’re freezing cold. The water entirely surrounding the ship is at freezing or slightly below. When they exhale, their breath condenses. There’s frost on the inside of the parts of the submarine. They’re all huddled together trying to conserve their body heat. They’re running low on oxygen and they’re exhaling carbon dioxide.”

On Thursday, the Coast Guard said the sub is believed to have imploded.

Wife of missing submersible pilot is descended from Titanic victims

Who was involved in the search and rescue effort for the Titan?

The search area spanned around twice the size of Connecticut and went down 212 miles into the ocean, according to The Associated Press.

The U.S. Navy, Canadian Coast Guard and OceanGate Expeditions were all involved in the search and rescue, per USA Today. A French team, a submariner from the British Royal Navy and experts from the Woods Hole Oceanographic Institution have also joined the effort.

The search and rescue team used “aircraft fitted with sonar, various sea vessels and deep-sea exploration tools” in its effort, per the New York Post.

How safe is the Titan?

More than three dozen people in the submersible craft industry signed a joint letter in 2018, “warning of possible ‘catastrophic’ problems with the submersible’s development and its planned mission to tour the Titanic wreckage,” per The New York Times. The letter was sent to OceanGate CEO Rush, who is on board the missing sub.

The letter said, “Our apprehension is that the current experimental approach adopted by Oceangate could result in negative outcomes (from minor to catastrophic) that would have serious consequences for everyone in the industry,” per The New York Times.

In 2019, OceanGate published a blog post titled “Why Isn’t Titan Classed?” In part, the blog post said, “When OceanGate was founded the goal was to pursue the highest reasonable level of innovation in the design and operation of manned submersibles. By definition, innovation is outside of an already accepted system. However, this does not mean that OceanGate does meet standards where they apply, but it does mean that innovation often falls outside of the existing industry paradigm.”

What is the deep sea like?

What does the Titanic wreckage look like?

The Titanic wreckage wasn’t discovered until 1985, according to NBC News. The wreckage was found around 350 miles off the coast of Newfoundland, Canada. Large amounts of the ship remain intact, like the steering motor. In photographs of the wreckage, it’s possible to see smaller items, like a coat and boots, as well as the remains of the dining room.

Boilers have been discovered, per NBC News, as well as the anchor.

Around the site of the Titanic, there’s bits of the wreck, according to NPR. The wreckage has been underwater for over a century and has signs of aging, like an iron-eating bacteria.

The bacteria is called Halomonas titanicae and eats the iron in the hull of the ship. Per the Smithsonian Institution, “They will eventually consume the entire ship, recycling the nutrients into the ocean ecosystem.”

Where did the Titanic sink?

The Titanic wreckage was discovered around 350 miles off the coast of Newfoundland, Canada, according to NBC News. It’s in the northern part of the Atlantic Ocean.