Disclaimer: This story has been updated with the officials declaring the submarine sunk. For the latest developments, see the update at the bottom.
Even military aircraft from the U.S. had joined the search for Indonesia's missing KRI Nanggala-402 submarine on Friday, as the hours counted down to 3:00 PM EDT — when Indonesian officials said the vessel would exhaust its oxygen supply.
While the search has yet to be called off, it is with deep regret that we observe the passing of this deadline. With it comes the dwindling likelihood that the submarine, along with its crew of 53, survived.
US officials offer words of support after sending aircraft to aid the search for the submarine
Officials had announced earlier that the submarine only had enough oxygen to last until 3:00 PM today (Friday, April 23). Assuming, of course, it was still intact.
The ship went missing Wednesday morning local time (approximately Tuesday, 3:00 PM EDT) after carrying out torpedo drills roughly 60 miles north of Bali, according to Indonesia's navy. After requesting and receiving permission to dive, it wasn't seen again — save for an oil slick observed close to the diving location.
Yesterday, Yudo Margono, chief of staff of Indonesia's navy, told a news conference that the diesel-powered submarine only possessed sufficient air to keep the crew alive until Saturday at dawn local time (Friday afternoon EDT).
Initially, the navy said it suspected the 44-year old vessel had sunk to a depth beyond 2,000 ft (609 m), which is nearly 400 ft deeper than its 1,640-ft (500-m) maximum depth. But hopes were momentarily raised late yesterday, when officials detected a "high magnetic" signature floating between 164 ft (50 m) and 328 ft (100 m) beneath the surface of the sea.
We are deeply saddened by the news of Indonesia’s lost submarine, and our thoughts are with the Indonesian sailors and their families. At the invitation of the Indonesian government, we are sending airborne assets to assist in the search for the missing submarine.— John Kirby (@PentagonPresSec) April 22, 2021
John Kirby, the Pentagon's press secretary, said on Twitter that the U.S. had sent "airborne assets to assist the search" after receiving an invitation from the Indonesian government. "We are deeply saddened by the news of Indonesia's lost submarine, and our thoughts are with the Indonesian sailors and their families," he wrote.
Kirby also said Secretary of Defense Lloyd Austin was meeting with his counterpart in Indonesia — Prabowo Subianto — to pursue other means of international assistance.
Countries raced to locate the missing Indonesian submarine
Australia, Malaysia, India, and Singapore have also sent ships or aircraft into the fray to aid the search for the missing submarine. All assisting nations join 24 Indonesian ships and a patrol plane mobilized for the emergency search throughout the day — with efforts focused on the area where aerial observations spotted the oil slick.
The Nanggala was German-built and admitted into the Indonesian fleet forty years ago, in 1981. It has since undergone a refit in South Korea, which was finished in 2012. All authorities said the vessel was in prime condition.
But even if officials locate the missing submarine, rescuing the crew will pose a serious challenge, said Director Frank Owen of the Submarine Institute of Australia to NBC News. "We know that the submarine is old, we know that the submarine has a depth rating of 250 meters — which means that it probably could survive to 400-500 meters (1,300 to 1,600 ft)," explained Owen, who said the local depth where the submarine went missing was 2,300 ft (700 m) deep.
Owen added that the submarine could only be discovered in one piece if it remained suspended in the water, although Owen himself is not part of the rescue efforts. "A submarine that loses propulsion means it can't actually drive itself back to the surface," he said. "And it might be too deep for putting air into the tanks to have any effect in terms of buoyancy."
"So it could be midwater and unable to use any electrical power," added Owen. "But the prognosis really isn't good."
As of writing, the search for the missing Indonesian submarine has not been called off. Working on an underwater vessel comes with natural risks.
With every dive, there is always the possibility that the submarine will never surface again. And, sadly, the situation looks grim for the brave crew of 53 people. We extend our best wishes to the sailors, their families, and loved ones.
UPDATE April 24, 5:50 AM EDT: Indonesian Navy declares the submarine sunk.
Indonesian officials announced that debris from the missing submarine has been found, dwindling the hopes of rescuing the 53 personnel on board. Items retrieved from the submarine include a bottle of lubricant and a device that protects a torpedo.
Air Marshall Hadi Tjahjanto is quoted saying “The objects found near the last location of the submarine are believed to be parts of the submarine." And he noted that “These objects would have never got out of the submarine unless there was pressure.”
The military is said to be planning to retrieve the vessel. Collin Koh, a research fellow who specializes in naval affairs and maritime security, told Al Jazeera: “The evacuation they’re talking about, I surmise they’re referring likely to the eventual retrieval of the debris or whatever is left of the submarine that can be salvaged, with the hope of at least retrieving the remains of the crew.”