A US undersea rescue vehicle has arrived at the spot where an Argentine submarine vanished on Nov. 15, but with little hope of finding its 44 crew members alive. Shortly before it disappeared, the ARA San Juan reported water had entered the sub through a snorkel and reached a battery connection tray in the prow, causing "a short circuit and the beginning of a fire, or smoke without flame," Navy spokesman Enrique Balbi said at a news conference Monday, per the AP. "They had to electrically isolate the battery and continue sailing underwater to Mar del Plata using another battery circuit." The captain reported that the issue was contained, but the sub never reached its base, per Reuters. Instead, a noise detected some 250 miles off Argentina’s southern coast suggests the 213-foot diesel-electric sub may have imploded, officials say.
If only submerged, the sub's oxygen supply would’ve run out after seven to 10 days. Yet some 4,000 personnel from 13 countries are continuing to search for the vessel. On Monday, a Norwegian ship delivered the US Navy's remotely operated underwater vehicle and pressurized rescue module near the sub's last known location. Despite the prognosis, some remain optimistic about what it could find. "I know my son is going to return. I know that he will come back alive," says the mother of crew member Celso Oscar Vallejos, per CBS News. "The final word hasn't been spoken." Other family members have accused the Navy of sending an unfit vessel out to sea. But Balbi said the San Juan underwent "a check of the whole operating system" two days before departing Ushuaia on Nov. 8. "The submarine doesn’t sail if that's not done," he said. (Read more submarine stories.)