The Titan submersible exploded amid intense water pressure in the deep North Atlantic, killing its pilot and four passengers instantly, experts said.
Marine researchers described the explosion as the worst possible outcome of all scenarios conceived during a desperate round-the-clock search to find the missing ship.
The plane went missing on Sunday and likely crashed the same day, according to an “anomaly” detected by the US Navy’s acoustics system, but international search efforts continued as officials did not consider the information definitive.
The Coast Guard announced the deaths from the “horrific blaze” on Thursday. Crews are still searching for evidence of what happened near the Titanic wreckage 12,500 feet (3,800 m) below the surface.
Experts warned that the intense pressure at the extreme depth could cause the Titan’s hull to burst, resulting in the immediate death of anyone aboard.
“I don’t think people can appreciate the amazing energy involved in the destructive process of the explosion,” Bob Ballard, a member of the team that found the wreckage of the Titanic, told ABC News in 1985. “It just pops out and literally rips everything to pieces.”
While Oceangate Expeditions, which owned and operated the ship, publicized the Titan’s huge cylinder-shaped cabin made of carbon-fiber, industry experts say it’s more likely than the titanium-made hulls used by most submarines. The size was different from the cabin.
A sphere is an “ideal shape” because the water pressure exerts the same force on all spheres, said Chris Roman, a professor at the University of Rhode Island’s Graduate School of Oceanography.
The larger internal volume of the 22-foot-long (6.7 m), 23,000-pound (10,432 kg) Titan—while still cramped for a maximum of five people—means it was subject to greater external pressure.
The water pressure at 12,500 feet (3,800 m) below the surface at the Titanic’s wreck site is approximately 400 atmospheres, or 6,000 pounds per square inch.
Arun Bansil, a physics professor at Northeastern University, compared that “huge” pressure to the force of a “whale biting someone”.
Although the Titan had a composite hull with inbuilt sensors that could withstand the high pressure near the ocean floor, any malfunction could result in an “instant explosion” in less than 40 milliseconds, said Associate Professor, director of the Shipbuilding Hub Eric Fusil said. University of Adelaide in Australia.
“The passengers might not have known what happened,” Bansil said.
Jasper Grahame-Jones, associate professor of mechanical and marine engineering at the University of Plymouth in the United Kingdom, said the Titan had undergone more than two dozen deep-sea dives, causing repeated stress on the hull.
This stress could potentially lead to delamination, which is the horizontal splitting of the carbon-fibre hull, he said.
Neither the Coast Guard nor Oceangate Operations have provided details on the explosion.
A similar disaster occurred in 1963 when the USS Thresher, a nuclear-powered submarine, exploded possibly when it exceeded “test depth” after a series of other failures. 129 sailors and civilians were killed on a routine test dive near Cape Cod.
