As an Indonesian navy submarine crewed by 53 men glided below the surface of the Bali Sea during a routine training exercise, it may have been hit by an invisible but powerful force that dragged them to the deep.
Indonesian navy officials suspect an internal solitary wave, known to occur in the seas around Bali, may have caused the sinking of KRI Nanggala 402, and the loss of its 53 crew.
The vessel sank to a depth of 838 meters, far beyond the reach of rescuers.
As the personal effects of crew members floated up and the oxygen supply on board slowly dwindled, officials said there was no chance anyone survived.
The question remained: What went wrong?
Many theories have been put forward but authorities now say there is evidence an underwater wave — that can exert an intense vertical pull below the sea surface — occurred in the Bali Sea around the very time the submarine disappeared last Wednesday morning.
