Argus disembarked the survivors at San Francisco on 3 November 1944. They described I-12 as a very large submarine, painted black or dark grey above the waterline and light grey below it, with a horizontal stripe running around her stern. Sources differ on casualties during the sinking and subsequent massacre, but at least six men were killed, one source claims that four crewmen, five Navy Armed Guard personnel, and the U.S. Army cargo security officer were left missing and presumed dead, and another specifies that 10 men died. Because John A. Johnson had broken in half, the Japanese erroneously credited I-12 with sinking two ships. A U.S. Navy hunter-killer group centered around the escort carrier began to search for I-12, and TBM Avenger aircraft from Corregidor reported that they attacked unidentified submarines on 2 and 4 November 1944. Some sources have claimed that the New Zealand four-masted barque sighted I-12 at on 12 November 1944, but this hypothesis largely has been discredited, and according to one source it is more likely that Pamir sighted the U.S. Navy submarine . Loss On 13 November 1944, the U.S. Navy minesweeper and the United States Coast Guard-manned U.S. Navy patrol frigate were escorting a six-ship convoy at about the midpoint of its voyage from Honolulu to San Francisco when at 12:32 Ardent′s sonar detected a submerged submarine ahead of the convoy west-southwest of Los Angeles, California. Ardent attacked first at 12:41, firing a 24-charge pattern of Hedgehog projectiles, and again at 12:46 with a second Hedgehog pattern. No projectiles hit the submarine. Rockford left her escort station to assist, and fired her first Hedgehog barrage of 13 projectiles at 13:08; 15 seconds later her crew heard either two explosions before a large underwater detonation rocked the ship, or three distinct detonations followed four minutes later by numerous underwater explosions, according to different sources. Ardent carried out two more Hedgehog attacks and Rockford dropped 13 depth charges to ensure the submarine′s destruction. After more explosions Ardent and Rockford lost all contact with the submarine at either or , according to different sources. Diesel oil, air bubbles, and debris including teak deck planks, ground cork covered in diesel oil, pieces of varnished mahogany inscribed in Japanese, a wooden slat from a vegetable crate with Japanese writing and advertisements on it, and a piece of an instrument case inscribed with Japanese characters. Both Ardent and Rockford