KITTERY, Maine —
The Navy believes sea water sprayed onto an electrical panel, shorting it out and causing an emergency shutdown of the nuclear reactor.
The submarine alerted the USS Skylark, a rescue ship trailing it, that it was attempting to surface by emptying its ballast tanks. But that system failed, and the sub descended below crush depth.
Understanding their dire situation, Navy crew members and civilian technicians would have scrambled to close valves to try to stem the flooding, struggled with a ballast system disabled by ice, and worked to restore propulsion by restarting the reactor, a 20-minute process.
Their deaths would have been instant because of the force of the violent implosion. The sub’s remnants came to a rest on the ocean floor at a depth of 8,500 feet.
There was nothing the divers on the Skylark could do.
“It’s one of those times when there’s silence,” recalled Danny Miller, one of the Skylark divers, now 70 and living in Farmington, Mo. “You don’t know what to say. You don’t know how to feel. You just know something tragic has happened.”
The Thresher wreckage covers a mile of ocean floor, according to University of Rhode Island oceanographer Robert Ballard, who used his 1985 discovery of RMS Titanic as a Cold War cover for the fact that he had surveyed the Thresher on the same mission.
“It was like someone put the submarine in a shredding machine,” Ballard said in a recent interview. “It was breathtaking. There were only a couple of parts that looked like a submarine.”
Word of the disaster spread quickly.
Paul O’Connor, now a union president at Portsmouth Naval Shipyard, remembers seeing the bulletin on TV. He was 6. Barbara Currier, whose husband, Paul, was a civilian worker on the Thresher, was shopping with her daughters when she heard the news on the radio in a store.