'True explorers': The 5 passengers who died on the missing Titanic submersible

Five men, including one teenager, have been declared dead days after they left for a voyage in a 22-foot submersible to see the wreckage of the Titanic in the North Atlantic Ocean.

OceanGate, the company that hosted the mission on the Titan submersible to the Titanic, said Thursday that the entire crew – including its founder and CEO who was the pilot in the mission – were “lost at sea.” The U.S. Coast Guard also announced Thursday that rescue teams had found debris from the ship on the ocean floor “consistent with catastrophic loss of the pressure chamber.”

The passengers were well known for their devotion to extreme exploration, desire to collect artifacts from the Titanic or their exorbitant wealth. Each paid $250,000 to ride on the submersible. The Coast Guard said families of the men had been notified of their deaths.

"These men were true explorers who shared a distinct spirit of adventure, and a deep passion for exploring and protecting the world’s oceans. Our hearts are with these five souls and every member of their families during this tragic time," OceanGate said in a statement Thursday.

Rear Admiral John Mauger of the U.S. Coast Guard said during a press conference Thursday he did not know whether the Coast Guard would be able to recover the bodies.

"This is an incredibly unforgiving environment down there on the seafloor," he said.

For live updates on this disaster, read USA TODAY’s live blog here. The passengers on the sub were:

OceanGate's CEO Stockton Rush

Stockton Rush, 61, founded OceanGate in 2009. He was also the co-founder of OceanGate Foundation, a non-profit organization "which aims to catalyze emerging marine technology to further discoveries in marine science, history, and archaeology," according to the company's website.

Rush said at a conference in Seattle last year: “One of the reasons I started the business was because I didn’t understand why we were spending 1,000 times as much money to explore space as we were to explore … the oceans. There is no private access to the deep ocean, and yet there’s all this life to be discovered.”

At the same conference, he also said submarine safety programs were “over the top in their rules and regulations.”

Before graduating from Princeton University with a degree in aerospace engineering in 1984 and obtaining a master’s degree in business administration from the University of California in 1989, Rush had obtained his captain’s rating at the United Airlines Jet Training Institute. He went on to oversee business ventures that included serving on the board of Seattle’s BlueView Technologies and as chairman of Remote Control Technology.

Greg Stone, the former executive vice president and chief scientist for Conservation International as well as a friend of Rush, said there was a need for advances in research submersibles.

“That’s the direction he was going in. And I liked where he was going,” Stone said.

But, he added, Rush “had the problem that a lot of frontier people have. And that is he was ahead of the regulations.”

Rush had familial ties to the Titanic, NPR reported. Stockton Rush was married to Wendy Rush, the great-great granddaughter of Isador and Ida Straus, who were on board the sinking Titanic ship together.

British billionaire explorer Hamish Harding

Hamish Harding, 58, was chairman of Action Aviation, a global sales company in business aviation. He held three Guinness World Records related to his explorations by plane and into the deep ocean. He had also been to space.

He had been looking forward to his Titan ride. “Due to the worst winter in Newfoundland in 40 years, this mission is likely to be the first and only manned mission to the Titanic in 2023," Harding wrote in a Facebook post Saturday, the day before the Titan voyage, according to the New York Times. "A weather window has just opened up and we are going to attempt a dive tomorrow. We started steaming from St. Johns, Newfoundland, Canada yesterday and are planning to start dive operations around 4am tomorrow morning. Until then we have a lot of preparations and briefings to do."

Richard Garriott de Cayoux, president of The Explorers Club, mourned the loss of his friends Harding and Paul-Henry Nargeolet on Twitter in a letter Thursday to “fellow explorers.”

“They were both drawn to explore, like so many of us, and did so in the name of meaningful science for the betterment of mankind,” he wrote. “Their memories will be a blessing and will continue to inspire us in the name of exploration.”

French maritime and Titanic expert Paul-Henri Nargeolet

Paul Henri-Nargeolet, 73, was director of Underwater Research for E/M Group and RMS Titanic, Inc. He successfully dived in a submersible to the site of the Titanic wreckage 37 times and "supervised the recovery of 5,000 artifacts," according to EMGroup's website, which also says he's "widely considered the leading authority on the wreck site."

"Born in Chamonix, France, P.H. lived in Africa for 13 years with his family and at 16 returned to France to complete his studies in Paris. He later joined the French Navy for a career that spanned 22 years and saw him rise in the ranks to Commander," according to the company site.

“I really hope they will find them all safe,” his daughter Sidonie Nargeolet said prior to Thursday’s announcement.

Dive expert David Mearns called Harding “a terrific character," and said Nargeolet was “almost a legend really in the field of deep sea exploration,” BBC reported.

Shahzada Dawood

Shahzada Dawood, 48, was one of the richest men in Pakistan and served as vice chairman of Pakistani Engro Corporation, a Pakistani conglomerate founded as a fertilizer company, where he worked for 20 years. He was on the board of trustees for the Dawood Foundation, an education nonprofit, and on the board of the SETI Institute, a non-profit research organization.

Dawood had over two decades of experience “in corporate governance” and “ the transformation of industries, including growth and innovation opportunities through mergers and acquisitions of diversified public-listed companies across textiles, fertilizers, foods, and energy,” his profile on the World Economic Forum site reads.

"He aspires to a sustainable future and believes in inclusive business models involving low-income communities building value chains along business interests," the profile states.

He is survived by his wife, Christine Dawood, and his daughter, Alia Dawood.

Suleman Dawood

Suleman Dawood, 19, loved science fiction, solving Rubik’s Cubes and playing volleyball, the New York Times reported. He was studying at the University of Strathclyde in Glasgow, according to the BBC.

Shahzada Dawood's older sister told NBC News she was "absolutely heartbroken" over the deaths.

"I feel like I’ve been caught in a really bad film, with a countdown, but you didn’t know what you’re counting down to," Azmeh Dawood said. "I personally have found it kind of difficult to breathe thinking of them."

She also said her nephew Suleman told one of their relatives that he was “terrified” about the voyage. She told NBC News Suleman went on the trip with his dad because he wanted to make his dad happy and it fell on the Father's Day weekend.

“I am thinking of Suleman, who is 19, in there, just perhaps gasping for breath… It’s been crippling, to be honest,” she told the news outlet.

In a letter to the “friends, followers and community of the SETI Institute” Thursday, CEO Bill Diamond shared the news of the deaths of Dawood and his son.

“Shahzada was passionately curious and an enthusiastic supporter of the SETI Institute and our mission, being directly involved in philanthropic programs in education, research and public outreach,” said Diamond. “He will be deeply missed by all who knew him, especially his fellow Trustees and the leadership of the SETI Institute.”

The Associated Press contributed to this report.

This article originally appeared on USA TODAY: Titanic submarine implosion victims: The 5 men who died on Titan trip