'They would have died instantly': What could have happened during the Titanic sub's 'catastrophic implosion'

A "catastrophic implosion," such as that believed to have destroyed the Titan submersible, would have happened with incredible force and speed given the crushing water pressure on the floor of the ocean.

The remains of the Titanic rest on the seabed in the North Atlantic at a depth of some 3,800 meters (12,400 feet).

At sea level, atmospheric pressure is 14.7 pounds per square inch (psi). Water pressure at the depth where the ocean liner lies is equivalent to around 400 atmospheres, nearly 6,000 psi. As a comparison, the bite of a large great white shark exerts a force of nearly 4,000 psi, according to Scientific American.

In an implosion caused by a defect in the hull or for some other reason, the submersible would collapse in on itself in milliseconds, crushed by the immense water pressure.

A former US Navy physician said the passengers "would have died instantly" in this case. They wouldn't have even known there was a problem, Dale Mole was quoted as saying in a BBC report.

Being stuck in the sub with limited oxygen supply would have been worse, he said. "You can just imagine what it would have been like... it's cold, your oxygen is running out," the expert told the BBC.

The Titan, built by OceanGate Inc. of Everett, Washington, was designed to sustain the extreme water pressure at the depth of the Titanic and had made previous dives to the wreck.

But safety concerns had been raised, most notably in a lawsuit involving OceanGate's former director of marine operations, David Lochridge, who was fired in 2018 after warning about the Titan's "experimental" carbon fibre hull.

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