From The New York Times:
For the first time since World War II, a torpedo launched from a U.S. Navy submarine struck a vessel in combat, sending the Iranian frigate Iris Dena to the bottom of the Indian Ocean near Sri Lanka.
The submarine, which the Pentagon has yet to identify, carried out the attack on Wednesday. Later that morning, the Defense Department released a video of a single torpedo detonating under the Iris Dena’s stern, sending a large plume of water skyward. The frigate’s hull can be seen tearing apart along its port quarter above the waterline. At a Pentagon briefing, Defense Secretary Pete Hegseth called the sinking “quiet death,” while Gen. Dan Caine, the chairman of the Joint Chiefs of Staff, spoke about it more dispassionately, saying the torpedo achieved “immediate effect.”