Spain, is bombed by German Luftwaffe. 1942 – Benxihu Colliery accident in Manchukuo leaves 1549 Chinese miners dead. 1943 – The Easter Riots break out in Uppsala, Sweden. 1944 – Georgios Papandreou becomes head of the Greek government-in-exile based in Egypt. 1944 – Heinrich Kreipe is captured by Allied commandos in occupied Crete. 1945 – World War II: Battle of Bautzen: Last successful German tank-offensive of the war and last noteworthy victory of the Wehrmacht. 1945 – World War II: Filipino troops of the 66th Infantry Regiment, Philippine Commonwealth Army, USAFIP-NL and the American troops of the 33rd and 37th Infantry Division, United States Army are liberated in Baguio and they fight against the Japanese forces under General Tomoyuki Yamashita. 1954 – The Geneva Conference, an effort to restore peace in Indochina and Korea, begins. 1954 – The first clinical trials of Jonas Salk's polio vaccine begin in Fairfax County, Virginia. 1956 – , the world's first successful container ship, leaves Port Newark, New Jersey, for Houston, Texas. 1958 – Final run of the Baltimore and Ohio Railroad's Royal Blue from Washington, D.C., to New York City after 68 years, the first U.S. passenger train to use electric locomotives. 1960 – Forced out by the April Revolution, President of South Korea Syngman Rhee resigns after 12 years of dictatorial rule. 1962 – NASA's Ranger 4 spacecraft crashes into the Moon. 1962 – The British space programme launches its first satellite, the Ariel 1. 1963 – In Libya, amendments to the constitution transform Libya (United Kingdom of Libya) into one national unity (Kingdom of Libya) and allows for female participation in elections. 1964 – Tanganyika and Zanzibar merge to form the United Republic of Tanzania. 1966 – The magnitude 5.1 Tashkent earthquake affects the largest city in Soviet Central Asia with a maximum MSK intensity of VII (Very strong). Tashkent is mostly destroyed and 15–200 are killed. 1966 – A new government is formed in the Republic of the Congo, led by Ambroise Noumazalaye. 1970 – The Convention Establishing the World Intellectual Property Organization enters into force. 1981 – Dr. Michael R. Harrison of the University of California, San Francisco Medical Center performs the world's first human open fetal surgery. 1982 – Fifty-seven people are killed by former police officer Woo Bum-kon in a shooting spree in South Gyeongsang Province, South Korea. 1986 – The Chernobyl disaster occurs in the Ukrainian