Rescuers continued an urgent search Friday for an Indonesian submarine that disappeared two days ago and has less than a day’s supply of oxygen left for its 53 crew. EuroNews reports that the KRI Nanggala 402 went missing after its last reported dive Wednesday off the resort island of Bali, and concern is mounting the submarine may have sunk in waters too deep to reach or recover. More than 20 navy ships, two submarines and five aircraft were mobilized for searches on Thursday and similar massive search operations are expected today. Singaporean and Malaysian rescue ships are set to arrive in the area from Saturday to Monday, and other nations have also offered assistance. The biggest concern is that the submarine is expected to run out of oxygen by around 3 am on Saturday.