There are five people on board and at the time of writing this post, they had about 1 day of oxygen left to keep them alive. A representative of the United States Coast guards was explaining the difficulties of rescuing the crew.
He explained how the ocean is vast and their equipment is limited. The crew were alive but they can't be removed from the submarine in the deep ocean because they would be crushed by the water pressure and it may be too difficult to raise the submarine before they run out of oxygen.
I hope they can rescue them before their air runs out.