"S-32" departed the Attu area early on the morning of 17 March. On 20 March, she moored at Dutch Harbor and, nine days later, she again sailed west. En route to Attu, cold weather caused icing on the superstructure, but the seas remained fairly calm and the sun was occasionally visible. On 3 April, however, as she approached Attu, more normal Aleutian weather closed in. From then to 16 April, snow and rain storms were almost continuous, seas were rough, winds were strong, and periods of sunlight were limited. At 01:57 on 10 April, while patrolling on a north-south line out of Holtz Bay, "S-32" picked up a target on radar, some away. Ten minutes later, a second smaller ship was detected ahead of the first target. Five minutes after the appearance of the second ship on the screen, the first ship was sighted, range about . "S-32" launched four torpedoes. Two very loud explosions were heard and were followed by distant rumblings. At 0219, at a range of just over , all traces of the ships disappeared from the screen.