Four years ago on this very day, the South Korean warship Cheonan was sunk in a torpedo attack blamed on North Korea.
To remember the 46 South Korean sailors who lost their lives that day, a memorial ceremony was held at Daejeon National Cemetery this Wednesday morning.
Thousands of people, including families of the victims and high-ranking government officials were in attendance.
President Park Geun-hye wasn't able to attend the event, as she's currently in Europe, but did send a special statement, in which she emphasized the importance of reunification and said a strong military was needed to achieve it.
President Park also called on South Korea's armed forces to retaliate against any further provocations by the North.