in history up to this time, and the first with a confirmed death toll exceeding 100. June 30 – The first roll-on/roll-off ferry crossing of the English Channel, Dover–Boulogne, takes place. July July 3 – The first ascent of Nanga Parbat in the Pakistan Himalayas, the world's ninth highest mountain, is made by Austrian climber Hermann Buhl alone on the German–Austrian expedition. July 9 – The U.S. Treasury formally renames the Bureau of Internal Revenue; the new name (which had previously been used informally) is the Internal Revenue Service. July 10 – The Soviet official newspaper Pravda announces that Lavrentiy Beria has been deposed as head of the NKVD. July 17 – The greatest recorded loss of United States midshipmen in a single event results from an aircraft crash near NAS Whiting Field. July 26 – Fidel Castro and his brother lead a disastrous assault on the Moncada Barracks, preliminary to the Cuban Revolution. July 27 – The Korean War ends, with the Korean Armistice Agreement: The United Nations Command (Korea) (United States), People's Republic of China and North Korea sign an armistice agreement at Panmunjom, and the north remains communist, while the south remains capitalist. August August 5 – Operation Big Switch: Prisoners of war are repatriated to the United States after the Korean War. August 8 – Soviet prime minister Georgi Malenkov announces that the Soviet Union has a hydrogen bomb. August 12 The 1953 Ionian earthquake of magnitude 7.2 totally devastates Cephalonia and most of the other Ionian Islands, in Greece's worst natural disaster in centuries. Soviet atomic bomb project: "Joe 4", the first Soviet thermonuclear weapon, is detonated at Semipalatinsk Test Site, Kazakh SSR. August 13 – Four million workers go on strike in France to protest against austerity measures. August 15–19 – Cold War: 1953 Iranian coup d'état – Overthrow of the democratically elected Prime Minister of Iran, Mohammad Mosaddegh, by Iranian military in favour of strengthening the monarchical rule of the Shah, Mohammad Reza Pahlavi, with the support of the United States Central Intelligence Agency (as "Operation Ajax") and the United Kingdom. August 17 – The first planning session of Narcotics Anonymous is held in Southern California (see October 5). August 20 – The French government ousts King Mohammed V of Morocco, and exiles him to Corsica. August 22 – The last prisoners are repatriated from Devil's Island to France. August 25 – The