US submarine sank an Iranian warship in international waters for the first time since WWII

A U.S. submarine sank an Iranian warship in the Indian Ocean

Cora Smith, Editor

March 9, 2026

An Iranian warship was struck by a US submarine torpedo, Secretary of Defense Pete Hegseth told reporters on Wednesday.( US Department of Defense/ March, 3, 26 )

In a first since World War II, a U.S. Navy submarine used a torpedo to sink an enemy warship, the Pentagon confirmed Wednesday ( NavyTimes | J.D Simkins / March, 03, 26 )

As of Wednesday, March 3rd, US submarine sank an Iranian warship, in international waters ending the lives of more than 80 crew members, being a rare instance of a submarine torpedoing a ship since World War 2.

The attack, which took place in international waters approximately 600 kilometers off the southern coast of Sri Lanka, sent the 1,500-ton vessel to the bottom of the Indian Ocean, leaving an estimated 60 sailors unaccounted for.

According to AP News article on the matter, Sri Lanka’s navy said it had responded to a distress signal from the IRIS Dena, but by the time it reached the location, there was no sign of the ship, just patches of oil and sailors floating in the water. (Saaliq , Mar, 5, 26 ).

The IRIS Dena is an Iranian-produced frigate armed with surface-to-air and anti-ship missiles, as well as torpedoes. It can also carry one helicopter ( AP Photo / Picture Alliance / February, 26 )

Sri Lanka’s navy pulled out a total of 32 survivors from the water and recovered 87 bodies from the Iranian frigate IRIS Dena.

Iran identified the vessel as the Iris Dena and pledged to seek vengeance for what it called an “atrocity.”

Written in a CNN News article, “An American submarine sunk an Iranian warship that thought it was safe in international waters,” Hegseth, U.S’s Secretary of War said during a press conference at the Pentagon. “Instead, it was sunk by a torpedo.” (Britzky , Feb, 24, 26 ).