The sinking of the Iranian frigate Iris Dena in the Indian Ocean is the first time a U.S. submarine has sunk a ship in the water since World War II.

IRIS Dena was a Muj-class frigate of Iran’s Southern Fleet, carrying a crew of approximately 180 people. It was equipped with heavy artillery, surface-to-air missiles, anti-ship missiles, torpedoes, and could also carry helicopters.

The ship was believed to be returning to Iran from joint military exercises off India’s east coast. According to the London paper, telegraphThe ship’s commanders had attended a naval conference in India with the US Navy chief before being torpedoed on the way home.

Earlier, the US military had already destroyed 17 Iranian ships and said its goal was to sink “its entire navy.”

Sri Lanka’s foreign minister said the country’s navy responded to a distress call from IRIS Dena and began rescue operations at 6am (12pm Wednesday, AEDT). About 87 bodies were recovered and 32 people were taken to hospitals, he said.

This is the first time in nearly 50 years that a submarine has destroyed a major warship.

In May 1982, during the Falklands War, the British nuclear submarine Conqueror destroyed the Argentine cruiser ARA General Belgrano, killing 323 sailors.

In March 2010, the South Korean Navy’s small ship Cheonan was sunk by a North Korean submarine attack, killing 45 people.