Missing Titan sub likely intact but out of power, says expert who designed deepest-diving submersible

Engineer Ron Allum says missing tourist sub unlikely to have suffered a catastrophic implosion' but partial flooding could be preventing it from resurfacing

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The missing Titan submersible is unlikely to have suffered a catastrophic failure of its pressure hull, according to a deep-sea engineer who designed the vessel that film-maker James Cameron used to reach Earth's deepest point.

Ron Allum, an Australian deep-sea engineer and explorer, co-designed the Deepsea Challenger submersible that Cameron used in 2012 to reach the deepest-known point of Earth's seabed in the Mariana Trench.