All 5 Titanic sub passengers lost: World leaders, Hollywood director, explorers pay tributes

World leaders, entrepreneurs, explorers and an award-winning director have paid heartfelt tributes to the five-person crew of the ill-fated Titan submersible that was believed to have suffered a catastrophic implosion on its voyage down to the Titanic shipwreck.

The five men - Dubai-based British billionaire Hamish Harding, UK-based Pakistani businessman Shahzada Dawood and his son Suleman, former French Navy commander Paul-Henry Nargeolet, and Stockton Rush, CEO and founder of OceanGate Inc. – were called “true explorers who shared a distinct spirit of adventure, and a deep passion for exploring and protecting the world’s oceans.”

British Foreign Secretary James Cleverly tweeted: “Tragic news that those on the Titan submersible, including three British citizens, have been lost following an international search operation. The UK government is closely supporting the families affected and expresses our deepest condolences.

Pakistan's Foreign Office also offered condolences to the bereaved families. "Our deepest condolences to the Dawood family and the family of other passengers on the sad news about the fate of Titanic submersible in the North Atlantic," tweeted Mumtaz Zahra Baloch, the Foreign Office spokesperson on her official Twitter handle on late Thursday. She added: "We appreciate the multinational efforts over the last several days in search of the vessel."

Award-winning Titanic director James Cameron, meanwhile, paid tribute to Nargeolet. He told ABC News: ‘The legendary submersible dive pilot, he is a friend of mine. It is a very small community. I’ve known him for 25 years. ‘For him to have died tragically in this way is almost impossible for me to process.’

‘Our hearts are broken’

The president of The Explorers Club, a professional society for scientists, explorers and entrepreneurs founded in 1904, also paid rich and poignant tribute to the five men.

Richard Garriott de Cayeux wrote in an open letter: “Our hearts are broken. I am so sorry to have to share this tragic news. Our friends and fellow Explorers Club members Harding and Nargeolet are lost, along with Rush, Shahzada and his son Suleman, while trying to reach the RMS Titanic.”

He added: “Hamish is a dear friend to me personally and to The Explorers Club. He holds several world records and has continued to push dragons off maps both in person and through supporting expeditions and worthy causes. Paul-Henri was elected to the Club in 2001 and was one of the foremost experts on submersible expeditions to the Titanic.

• Missing Titanic sub: All 5 passengers 'sadly lost'; debris suggests 'catastrophic implosion'