Causes of Mysterious Submarine Disappearances Unclear 50 Years Later
The submarine had broken into three pieces, tragically confirming that all 53 crew members had perished. The exact cause of the sinking remains unknown. Indonesian officials have ruled out human error and have suggested a power failure or undersea wave may have forced the submarine to descend far below its crush depth of about 655 feet. The government plans to recover the submarine with help from China. Deep-water submarine sinkings are rare but always fatal, and their causes are hardly ever fully established. In 1968, for instance, four submarines from four countries were lost with all hands...
Source: businessinsider.com