A U.S. submarine torpedoed and sank an Iranian warship in the Indian Ocean near Sri Lanka, leaving more than 80 sailors dead in one of the most dramatic naval incidents of the conflict. The vessel, the IRIS Dena, one of Iran’s newest frigates, reportedly went down rapidly after being struck, leaving oil slicks, life rafts and debris scattered across the sea. U.S. Defense Secretary Pete Hegseth said an American submarine destroyed the Iranian warship after it was identified as a potential threat, calling the strike a rare modern example of a submarine sinking an enemy ship with a torpedo.
Sri Lankan authorities said the frigate had sent distress signals before losing contact, reporting around 180 people on board. Rescue teams later recovered dozens of survivors while many sailors were confirmed dead and others remain missing. The sinking marks a major escalation of naval confrontations linked to the wider U.S.–Iran conflict, raising concerns about the safety of international shipping routes and the potential expansion of the war into critical global sea lanes.