Hegseth: Iranian Warship Sunk by U.S. Submarine Torpedo

By Richard R. Burgess, Senior Editor

ARLINGTON, Va. — An Iranian warship has been sunk by a torpedo fired from a U.S. Navy submarine, the Secretary of War said. The action would be the first ship sunk by torpedo fired from a U.S. Navy ship since World War II.

Secretary of War Pete Hegseth said on March 4, 2026, that the Iranian ship was sunk in the Indian Ocean

According to the BBC, the sunken ship was the IRIS Dena, a guided-missile frigate that went down off the southern coast of Sri Lanka. The ship was one of six ships of the Moudge class.

According to Reuters, the Sri Lankan Navy rescued 32 people from the ship, of a crew estimated to number 180 members. At least 80 crew members died in the action.

The action represents the first sinking of an enemy warship by a U.S. submarine’s torpedo since World War II.

During the Falklands War, on May 2, 1982, the Royal Navy nuclear-powered attack submarine HMS Conqueror sank the Argentine Navy cruiser ARA Belgrano with a torpedo. The Belgrano was formerly the light cruiser USS Phoenix.

U.S. Navy submarines are armed with 21-inch Mark 48 21-inch diameter torpedoes.