Shortly after Italy's entry into World War II in June 1940, she was sunk by British torpedo bombers in Augusta, Sicily, but was later refloated and repaired.

[4] Leone Pancaldo was laid down by Cantieri Navali Riuniti at their shipyard in Riva Trigoso on 7 July 1927, launched on 5 February 1929 and completed on 30 November 1929.

[6] When Italy entered World War II, on 10 June 1940, Pancaldo was part of the 14th Destroyer Division, together with sisterships Ugolino Vivaldi, Antonio da Noli and Lanzerotto Malocello.

Radio intercepts, however, had alerted the Italian commands of the danger, and most of the fleet was transferred to other bases; only Pancaldo and Vivaldi, that had not yet completed refuelling, were left in the harbour when the Swordfish attacked.

Both destroyers opened fire with their anti-aircraft guns, but one of the torpedoes dropped by the planes hit Pancaldo, causing her to sink in a few minutes on a 30-meter bottom, with the loss of sixteen men.

[6] To lighten the ship before the salvage, many parts were removed, including her artillery and torpedo tubes; on 26 July 1941, a year after her sinking, Pancaldo was brought to the surface, and on 1 August she entered drydock.

After provisional repairs that enabled her to withstand a voyage at sea, on 27 October 1941 Pancaldo left Augusta heading for Genoa, where she underwent extensive reconstruction work in the Ansaldo shipyard, lasting till 17 November 1942.