Indonesia races to find missing submarine before it runs out of oxygen on Saturday

Jakarta (CNN) Concerns were mounting Thursday over the fate of an Indonesian submarine that went missing with 53 crew members on board, as a military official warned the vessel would run out of oxygen in three days.
Admiral Yudo Margono, the chief of staff of the Indonesian Navy, said the submarine has sufficient oxygen for 72 hours, based on calculations from when the vessel lost contact during a military exercise on Wednesday.
The German-made KRI Nanggala-402 asked for permission to dive, or submerge, at 3 a.m. local time Wednesday before losing contact, authorities said.
Margono said the submarine had just fired two torpedoes -- one with real ammunition and another with a practice warhead -- as part of training exercises in the Bali Strait, a stretch of water between the islands of Java and Bali that connects to the Indian Ocean and Bali Sea.
Answering questions on the submarine's condition before participating in the war simulation, Margono said the KRI Nanggala-402 and all of its crew are well prepared.
It last docked for maintenance in 2020 in Surabaya, a port city on the island of Java, he said.
The military suspects that an oil spill seen in aerial surveillance near the dive point on Wednesday came from the craft.
Margono said the Navy also found one object at the depth of 50-100 meters (approximately 164-328 feet) that was magnetic, meaning it likely came from the submarine.