Hamish Harding, a British businessman who was among the five people killed in the Titan implosion, was remembered as a "passionate explorer" by his loved ones.

"Hamish Harding was a loving husband to his wife and a dedicated father to his two sons, whom he loved deeply," a statement sent on behalf of his family and Action Aviation, the company he chaired, said. "To his team in Action Aviation, he was a guide, an inspiration, a support, and a Living Legend."

"He was one of a kind and we adored him. He was a passionate explorer -- whatever the terrain -- who lived his life for his family, his business and for the next adventure," the statement continued. "What he achieved in his lifetime was truly remarkable and if we can take any small consolation from this tragedy, it's that we lost him doing what he loved."

-ABC News' Mark Guarino

Explorer Robert Ballard, who was on the 1985 expedition that discovered the Titanic wreckage and has made many dives since, reacted to news of the implosion with ABC News on Thursday.

"It's very tragic what happened, I know the people that passed away," he said, adding that he's known OceanGate CEO Stockton Rush, who was piloting the vessel, for 20 years. "I know this was his dream, so my heart goes out to him and his family and the families of all the people who lost loved ones."

Ballard surmised the crew likely experienced difficulties and began to drop weights to ascend to the surface but "never made it."

"If you're on your way up and you're buoyant and you don't make it, it's a catastrophic implosion," he said.

"I don't think people can appreciate the amazing energy involved in the destructive process of an implosion," Ballard continued. "It just takes and literally shreds everything. So it's extremely powerful."

The Explorers Club reacted to news of the submersible's implosion, saying in a letter to members on Thursday: "Our hearts are broken."

President Richard Garriott de Cayeux noted that two of the passengers lost in the implosion -- Hamish Harding and Paul-Henri Nargeolet -- were members of the Explorers Club, while OceanGate CEO Stockton Rush was a friend of the society who had conducted lectures at its headquarters.

"Hamish Harding is a dear friend to me personally and to The Explorers Club," Garriott de Cayeux said. "He holds several world records and has continued to push dragons off maps both in person and through supporting expeditions and worthy causes."

Nargeolet was "one of the foremost experts on submersible expeditions to the Titanic," Garriott de Cayeux said.

"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 continued. "They pushed themselves in their entrepreneurial pursuits as they did in exploration."

In reacting to news of the OceanGate submersible implosion, "Titanic" director James Cameron told ABC News that he was "struck by the similarity of the Titanic disaster itself, where the captain was repeatedly warned about ice ahead of his ship and yet he steamed at full speed into an ice field."

Cameron, who has built his own submersible, was critical of OceanGate's use of a carbon-fiber hull, calling it "fundamentally flawed."

OceanGate CEO Stockton Rush, who was among the five passengers killed on the submersible, had previously said he believed a sub made with carbon fiber would have a better strength-to-buoyancy ratio than titanium.

The Hussain and Kulsum Dawood family has issued a statement expressing their condolences.

"It is with profound grief that we announced the passing of Shahzada and Suleman Dawood," the family said. "Our beloved sons were aboard OceanGate's Titan submersible that perished underwater. Please continue to keep the departed souls and our family in your prayers during this difficult period of mourning."

"We are truly grateful to all those involved in the rescue operations," they continued. "Their untiring efforts were a source of strength for us during this time. We are also indebted to our friends, family, colleagues and well-wishers from all over the world who have stood by us during our hour of need. The immense love and support we receive continues to help us endure this unimaginable loss."

"We extend our heartfelt condolences to the families of the other passengers on the Titan submersible," the family added. "At this time, we are unable to receive calls and request that support, condolences and prayers be messaged instead. Details of their final rites in this world will be announced soon."

-ABC News' Habibullah Khan