On 24 April 2021, Indonesian authorities declared that the Nanggala-402, a Navy submarine that went missing while conducting a naval exercise on 21 April, had sunk. Despite an intensive search and rescue operation involving naval assets from Singapore, Australia, India, Malaysia and the United States, the submarine was unable to be located. Its wreckage was later discovered on 25 April more than 800 metres below sea level. All 53 on board including the Navy’s submarine unit commander perished.