One of the co-founders of the firm behind the missing Titanic submersible fears there was an "instantaneous implosion" of the craft that CEO Stockton Rush was piloting with four passengers.
It comes as the US Coast Guard announced that a "debris field" has been found within the search area near the Titanic wreck.
Guillermo Söhnlein, who co-founded OceanGate with Stockton Rush, explained that their protocol for lost communications is for the pilot to surface the sub.
He believed that Stockton Rush, the missing pilot, would have followed this protocol. However, this could make it challenging to locate the submersible because the surface ship would not have known it was surfacing and would not have known where to look.
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He told the BBC: "I know that our protocol for lost comms is for the pilot to surface the sub. From the beginning I always thought that’s probably what Stockton would have done.
"In which case it becomes very difficult to find the sub because the surface ship wouldn’t have known it was coming up and wouldn’t have known where to look.
"My biggest fear through this whole thing watching the operations unfold is that they’re floating around on the surface and they’re just very difficult to find."
Mr Söhnlein acknowledged the possibility of a catastrophic event.
He mentioned that when operating at great depths, the pressure is immense, and in case of failure, it would result in an instantaneous implosion.
Mr Söhnlein added: "What I do know is regardless of the sub, when you’re operating at depth the pressure is so great on any sub that if there is a failure it would be an instantaneous implosion.
"If that’s what happened that’s what would have happened four days ago. If anything, I think we need to go back and learn from what’s happening, find out what’s happened, take those lessons and carry them forward."
The Titan was estimated to have about a four-day supply of breathable air when it launched Sunday morning in the North Atlantic — but experts have emphasized that was an imprecise approximation to begin with and could be extended if passengers have taken measures to conserve breathable air. And it’s not known if they survived since the sub’s disappearance.
