The nuclear-powered Project 949A Antey (Oscar II class) submarine K-141 Kursk sank in an accident on 12 August 2000 in the Barents Sea. It was taking part in the first major Russian naval exercise in more than 10 years. All 118 personnel on board were killed. The crews of nearby ships felt an initial explosion and a second much larger explosion but the Russian Navy did not realise that an accident had occurred and did not initiate a search for the vessel for over six hours. The submarine's emergency rescue buoy had been intentionally disabled during an earlier mission and it took more than 16 hours to locate the submarine which rested on the ocean floor at a depth of 108 metres (354 ft).