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On April 10, 1963, the USS Thresher, an atomic submarine, sinks in the Atlantic Ocean, killing the entire crew. One hundred and twenty-nine sailors and civilians were lost when the sub unexpectedly plunged to the sea floor roughly 300 miles off the coast of New England. On April 10, 1963, at just before 8 a.m., the Thresher was conducting drills off the coast of Cape Cod. At 9:13 a.m., the USS Skylark, another ship participating in the drills, received a communication from the Thresher that the sub was experiencing minor problems.
Other attempted communications failed and, only five minutes later, sonar images showed the Thresher breaking apart as it fell to the bottom of the sea. Sixteen officers, 96 sailors and 17 civilians were on board. All were killed.