"Sturgeon" pursued, but was unable to fire, as the target was traveling at . However, it slowed to about at midnight; according to crewman Yoshiaki Yamaji, it was to rendezvous with an escort of two destroyers. Unaware that it was carrying Allied prisoners of war and civilians, "Sturgeon" fired four torpedoes at "Montevideo Maru" before dawn of 1 July, causing the vessel to sink in only 11 minutes. According to Yamaji, Australians in the water sang "Auld Lang Syne" to their trapped mates as the ship sank beneath the waves.