Transcript for Desperate hunt for submarine and its 44 member crew

We turn now to the desperate hunt for a submarine and its 44-member crew. There is late word coming in tonight that they are now analyzing a noise that might have come from that submarine. The search hampered by fierce seas, as U.S. Navy equipment arrives to help in the search. ABC's Linzie Janis is in Argentina tonight. Reporter: Tonight, rescue teams facing these fierce winds and massive waves. Focusing their search zone after an Argentine naval ship picked up underwater noises while looking for that missing submarine. Officials urging caution. Those noses described as sustained, now being analyzed by the U.S. Navy. The U.S. Navy aircraft have very powerful computers to analyze these sounds to make sure this is, in fact, the argentinean submarine. Reporter: The Ara San Juan was last heard from five days ago. Its commander reporting an electrical fault. Now it's a race against time to find the 44 crew members on board. Including Argentina's first female submarine officer, Eliana MARIA Krawczyk. The families of the crew members gathering at the nay have base today. Carlos Mendoza waiting for news of his brother, Fernando. He says, "The truth is, the days go by, and not knowing anything at all just kills you. It kills you." And Linzie Janis is live from Argentina tonight, where the submarine was heading. And I know authorities there believe the sailors might be running out of time. They've been out of contact now for five days and may only have enough oxygen for two more days at the most? Reporter: That's right, David. The Argentine Navy says in a worst case scenario, if the submarine has sunk, it only has a total of a week's worth of oxygen. David? Linzie Janis, thank you.

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