Pieces of the submersible missing since Sunday near the wreck of the Titanic have been found.
Five different major sections were discovered by a robot working at the bottom of the Atlantic Ocean.
Experts have confirmed they belong to the Titan, which had 5 crew members - 3 of them were British citizens.
Rear Admiral John Mauger, from the US Coastguard, can't say whether any victims will be recovered.
"This is an incredibly unforgiving environment down on the sea floor - and the debris is consistent with a catastrophic implosion of the vessel."
Underwater robots are still gathering information about the disaster.
Former British Royal Navy submariner David Russell wants deep sea tourism to face tighter regulation.
"Maybe we should try and learn some lessons for this, so that the construction of submersibles is better in the future - and if that was the issue, what was wrong with this particular form of construction."
Meanwhile the director of the film Titanic says he wishes he'd 'spoken up' about concerns over the quality of the submersible.
James Cameron says he 'never experimented' with the technology used on their vessel.
He has been to the shipwreck his 1997 movie is based on 33 times.
