Indonesian officials working to determine how a military submarine with 53 crew members sunk earlier this month during a training exercise said the vessel may have been hit by an internal solitary wave in the treacherous waters off Bali.
Australia’s ABC.net.au reported that such waves are invisible but have the strength to drag a submarine down to dangerous depths. The report said that there have been several theories, but evidence seems to point to a wave that would not be evident on the surface of the water.
The report said Indonesian naval officials consulted satellite images from the region and determined that these kind of massive waves were in the area at the time of the sinking.
Rear Adm. Iwan Isnurwanto, the commander of the Indonesian Navy Command and Staff School, told the station that the wave may have "moved up from the bottom to the north, and there’s a trench between two mountains."
"There was nothing that they could do, no time to do anything... if the sub was brought down by such a wave. It likely angled [downward], causing all the crew members to roll down," Isnurwanto said, according to Nikkei Asia. "We have to do further investigation, but that is most likely what happened."
An underwater robot equipped with cameras documented the lost submarine lying in at least three pieces on the ocean floor at a depth of 2,750 feet.
The cause of the submarine’s sinking remains uncertain. The navy previously said an electrical failure could have left the submarine unable to execute emergency procedures to resurface. The report said other theories include a missile strike or catastrophic blackout.
The Associated Press contributed to this report.