PS-160T's voyage proceeded without incident until 12:32 on 13 November 1944, some west-southwest of Los Angeles, Calif., "Ardent"s sonar picked up a submarine contact. The minesweeper attacked, firing a 24-charge “hedgehog” pattern, and followed that up with a second pattern at 12:46. "Rockford" left her escort station to assist, and fired her first barrage of rockets from her “hedgehog” at 13"08. Two explosions followed, before an underwater detonation rocked the ship. While the ships in company took evasive action on signal from the convoy commodore in "U. S. Grant", "Ardent" carried out two more attacks and the frigate dropped 13 depth charges. Wreckage recovered on the scene—deck planks, ground cork covered with diesel oil, a wooden slat from a vegetable crate with Japanese writing and advertisements on it, pieces of varnished mahogany inscribed in Japanese, and a piece of deck planking containing Japanese builders’ inscriptions—indicated a definite “kill” that the Navy ultimately awarded to "Ardent" and "Rockford" equally.