The youngest passenger on board the Titan submersible was “terrified” ahead of the trip, his family has revealed. 

All five passengers are thought to have died following a "catastrophic implosion" on a voyage to see the wreck of the Titanic. 

In a statement, OceanGate, the company that organised the expedition, lauded them as “true explorers who shared a distinct spirit of adventure”. 

Two of the passengers were the British businessman Shahzada Dawood and his 19-year-old son Suleman. 

Speaking to NBC News, Suleman’s aunt, Azmeh Dawood, said her nephew "wasn't very up for it" and felt “terrified” but went as a Father’s Day present. 

"I feel disbelief," Ms Dawood told the broadcaster. 

"It's an unreal situation… 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. 

"I personally have found it kind of difficult to breathe thinking of them."

The other passengers were businessman Hamish Harding, explorer Paul-Henry Nargeolet and OceanGate CEO Stockton Rush.

Mr Rush’s widow, Wendy Rush, is the great-great granddaughter of two Titanic passengers - Isidor and Ida Straus.

Safety

Underwater robots are still gathering information about the disaster but there are already calls for better regulation of deep sea tourism. 

“Maybe we should try and learn some lessons from this, so that the construction of submersibles is better in the future,” former British Royal Navy submariner David Russell said. 

“If that was the issue, what was wrong with this particular form of construction?”

Main image: The Oceangate submersible "Titan". Picture by: Alamy.com