"Neptune" hit a fourth mine and quickly capsized, killing 737 crew members. The other 30 initially survived the sinking but they too died. As a result, only one was still alive when their carley float was picked up five days later by the Italian torpedo boat "Achille Papa". The sole survivor, Norman Walton, spent 15 months in an Italian prisoner of war camp. In 1991 Walton travelled to the small city of Nelson, New Zealand, to unveil a memorial to "Neptune". Of the 736 that perished, 150 were New Zealand sailors, including four from Nelson. A memorial service to "Neptune" and her crew is held each year in Nelson.