Pohang-class corvette

The Pohang class (Korean: 포항급, Hanja: 浦項級) corvette is a class of general purpose vessels operated by the Republic of Korea Navy. They have served in a coastal defense role during the late Cold War and post Cold War period. A total of 24 Pohang-class vessels were built, all constructed in South Korea. 21 vessels remain in service.

Sinking of ROKS Cheonan
At 21:21:57 (12:21:57 UTC) of 26 March 2010, an explosion (or two explosions) occurred for 1~2 seconds at the stern of ROKS Cheonan, causing a power stoppage and inflow of oil and seawater, and the ship heeled 90 degrees to starboard very quickly. When the crew went out to the deck, they found the stern already submerged. At 22:40, the Navy and the Coast Guard rescued 58 sailors, including the captain, from the crew of 104; 46 were killed. The ship sank around 01:00 on 27 March 2010.

The bow floated 6.4 km to the southeast from the explosion site, then submerged completely at 22:30 on 27 March 2010.

On May 20, 2010, a South Korean-led investigation group announced that all evidence pointed to a North Korean torpedo being responsible for the sinking of the Cheonan.