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Quiet death
As reported yesterday, Secretary of War Pete Hegseth said during an update to reporters on “Operation Epic Fury” in Iran that an Iranian warship was sunk near Sri Lanka by a torpedo launched by a US Navy submarine, the first time since World War II that a US submarine has sunk another vessel using a torpedo.
the first time since World War II that a US submarine has sunk another vessel using a torpedo.
“An American submarine sunk an Iranian warship that thought it was safe in international waters,” Hegseth said. “Instead, it was sunk by a torpedo. Quiet death.”
Chairman of the Joint Chiefs of Staff Gen. Dan Caine said that an Iranian vessel was “effectively neutralized” in a Navy “fast attack” using a single Mark 48 (Mk 48) torpedo. The US Navy achieved “immediate effect, sending the warship to the bottom of the sea.”
Initially it was reported that the Iranian warship sunk by the US Navy submarine was a Shahid Soleimani class corvette. Instead as reported on Mar. 4, 2026 by Reuters, the ship sunk was a 1,500-ton Moudge-class frigate IRIS Dena (75), which recently operated in the Bay of Bengal for exercises.
“We’ve destroyed more than 20 Iranian naval vessels, in addition to the frigate outside the area, one submarine and effectively neutralized at this point in time Iran’s major naval presence in theater out there,” the chairman said.
Video of US Navy submarine sinking Iranian Frigate IRIS Dena
The video featured in this post was first posted on social media website X by the Defense Department showing a ship before an underwater explosion broke the keel of the vessel at the stern.
According to USNI News, the incident marks the first time the war with Iran has expanded to US 7th Fleet.
Sri Lankan Navy, Coast Guard and Air Force conducted search and rescue operations and rescued Iranian sailors from the ship who were floating in the water. While the Sri Lankans did not find the Iranian ship, they did pull dead bodies from the water that an official said were from Dena.
However as noted by USNI News, a video on X showing an IRGC Navy Shahid Soleimani-class corvette surrounded by clouds of smoke was posted by CENTCOM. The same Command then said that the US Navy hit the Iranian ship. Based on the hull number in the video, the ship is IRIS Shahid Sayyad Shirazi.
Moudge-class frigate
IRIS Dena (75) (Persian: ناوشکن دنا) was a Moudge-class frigate in the Southern Fleet of the Islamic Republic of Iran Navy. She became the first ship sunk by a submarine in active combat since the ARA General Belgrano during the Falklands War, and the first by an American submarine since World War II.
Dena was the first Iranian ship equipped with the Iranian “Bonyan 4” engines. It had four engines, each generating 5,000 hp (3,700 kW) for a total power of 20,000 hp (15,000 kW). It had a bow thruster system for increased maneuverability. The ship had slightly canted sides compared to its predecessor, designed to reduce its radar signature. It was equipped with an Asr phased array radar.
According to Wiki, the ship carried a significantly greater armament compared with the frigates of the same-class. Dena was equipped with a vertical launching system, a first for an Iranian ship. The ship was equipped with surface-to-air and anti-ship missiles. It had an armament of four Ghader anti-ship missiles, a 76 mm Fajr-27 naval gun, a 40 mm Fath-40 AA cannon, a 30 mm Kamand anti-aircraft defense cannon, two 20 mm Oerlikon cannons, two 12.7 mm heavy machine guns, and two 533 mm Valfajr triple torpedo launchers.
Photo credit: U.S. Navy, mojnews.com Mohammad Agah via Wikipedia
