Augusta, Sicily
On 16 June 1940, under the command of Lieutenant Commander C. A. Rowe, "Grampus" was laying mines in the Syracuse and Augusta, Sicily area. She was seen by the Italian "Spica"-class torpedo boat "Circe", which was on anti-submarine patrol with , , and "Polluce". Within a very short time, "Grampus" was destroyed. Wreckage came to the surface along with air bubbles and oil. "Polluce" was credited with the kill. There were no survivors. Some sources give the date of this action as 24 June 1940.