On March 26, 2010, an unprecedented incident in which ROKS Cheonan was sunk by a surprise torpedo attack by a North Korean submarine occurred, resulting in the death of 46 crew members. The Ministry of National Defense organized the Civilian-Military Joint Investigation Group on March 31 in order to clearly identify the cause of the sinking as well as the entity responsible for the incident. The Civilian-Military Joint Investigation Group proceeded with the investigation with the participation of civilian and foreign experts to ensure objectivity and credibility. The final investigation results were announced on May 20. The Civilian-Military Joint Investigation Group reported the investigation results to the UN Security Council on June 14. As a result, UN Security Council Presidential Statement that acknowledges and condemns North Korea's culpability in the incident was unanimously adopted. North Korea continues to deny the facts and has heightened its threats of military provocations, claiming that the Republic of Korea fabricated the investigation results.