Iran Confirms 104 Killed, 32 Wounded When US Submarine Sank Frigate Dena Off Sri Lanka

The Iranian army officially confirmed on Day 9 that at least 104 people were killed and 32 wounded when a US submarine sank the Iranian frigate Dena approximately 19 nautical miles off Galle, Sri Lanka's southern port city. The sinking occurred on Wednesday (Day 5) and was confirmed by US Defense Secretary Hegseth at the time. The updated figure of 104 killed — up from the initial 87 reported — makes the Dena sinking the single largest loss of Iranian military personnel in any individual incident of the war. The confirmation comes as Iran officially acknowledges the full scale of the loss. The Dena was a Moudge-class corvette/frigate — a domestically produced Iranian warship representing the most capable surface combatant in the Iranian navy. Its sinking by a US submarine using a Mark 48 ADCAP torpedo is the first torpedo sinking of a warship since the Second World War (excluding the Belgrano, 1982 Falklands conflict), a historic milestone in naval warfare. The loss of 104 sailors in a single incident represents a significant psychological blow to the Iranian military and the IRGC's naval ambitions. The Indian Ocean location — far from the Persian Gulf — demonstrated US naval power projection capability and Iran's inability to protect its assets beyond the Gulf.