She was sunk by gunfire, Frost taking 13 of her crew prisoner. A two-hour attack on 3 July, during which the target submarine attempted to torpedo Frost, resulted in the sinking of U-154.
The sinking of U-154 occurred after a two-hour confrontation on July 3, in which the submarine was severely damaged by gunfire. Despite its efforts to retaliate, the vessel ultimately succumbed to the attack and was captured by Frost, who took 13 German crew members prisoner.