Indonesian Navy Says Oil Slick, Debris Proof That Submarine Sank, Killing 53

Indonesian government officials said Saturday that a missing submarine had likely sunk below it's so-called crush-depth and broken apart, killing all 53 crew members aboard following a massive technological error Wednesday.

Indonesian navy and military officials including chief Hadi Tjahjanto highlighted an oil slick and debris on the surface of the water near where the submarine's last recorded dive was Wednesday. He and Navy Chief Yudo Margono told reporters they believe that these items from the submarine were clear proof that KRI Nanggala 402 sank with a total loss of life. The submarine was conducting a routine training exercise in the waters north of Bali.

Navy officials said the exact cause for the disappearance is still uncertain, but that a massive electrical failure could have caused it to fall well below the depth that its hull could withstand. The Navy said the submarine fell to a depth of 600 to 700 meters, or 2,000 to 2,300 feet, which is much deeper than the 200-meter depth at which the German-built vessel would have buckled under the water pressure.

"If it's an explosion, it will be in pieces. The cracks happened gradually in some parts when it went down from 300 meters to 400 meters to 500 meters ... If there was an explosion, it would be heard by the sonar."

Numerous Indonesian residents shared "Pray for KRI Nanggala 402" posts on social media Saturday after the government said a helicopter spotted the oil slick near where the submarine had last submerged. The submarine only had enough oxygen in supply to last underwater for three days, a time period that ended at 3 a.m. this morning, local time.

Sonar-equipped Australian warships and four Indonesian aircraft joined 20 Indonesian ships in searching for the submarine since its disappearance. An American reconnaissance plane had been expected to join the search this weekend.

The Nanggala 402 has been in service in Indonesia since 1981 and was carrying 49 crew members and three gunners as well as the submarine's commander, the Indonesian Defense Ministry said in remarks reported by the Associated Press. Normally, sailors can survive several days underwater without re-surfacing, but military officials insisted that something went tragically wrong.

"With the authentic evidence we found believed to be from the submarine, we have now moved from the 'sub miss' phase to 'sub sunk,'" Margono said at the Saturday press conference.

Newsweek reached out to representatives for Indonesia based in Washington D.C., but did not hear back by time.

Indonesia Submarine Search
Indonesian marine police prepare to take part in the search operation for an Indonesian Navy submarine that went missing during military exercises off the coast of Bali, at Celukan Bawang port in Buleleng province on April 22, 2021. SONNY TUMBELAKA/AFP via Getty Images