On this day in 1963, the USS Thresher sinks off the coast of Cape Cod. Sadly, a rescue ship was floating helplessly above the wreckage, listening to the sounds of the submarine breaking up below.The tragedy shocked the naval community. Thresher was considered one of the premier submarines of its time. It was fast—and quiet! It could dive deeper than other submarines. It should have been a valuable asset for the United States during the Cold War.Instead, it sank and imploded.Thresher was a relati