The Korean War began on June 25, 1950, when troops from Communist North Korea invaded South Korea. The United Nations called the invasion a violation of international peace and demanded that the Communists withdraw. Sixteen UN member nations sent troops to help the South Koreans, with the United States sending more than 90 percent of the troops, military equipment, and supplies. Over 580,000 UN and South Korean troops were killed in the conflict. Many brave women serving in the U.S. Navy Nurse Corps in the Korean combat zone provided care to wounded United States soldiers fighting as part of the UN force against the North Koreans. The war ended on July 27, 1953, when the UN and North Korea signed a truce, but a permanent peace treaty has never been signed.