passenger ship capsizes and sinks in the Gulf of İzmit, Turkey; at least 300 die. March 2 – A British Commonwealth Trans-Antarctic Expedition team, led by Sir Vivian Fuchs, completes the first overland crossing of the Antarctic, using snowcat caterpillar tractors and dogsled teams, in 99 days, via the South Pole. March 8 – The is decommissioned, leaving the United States Navy without an active battleship for the first time since 1896 (she is recommissioned October 22, 1988). March 11 – A U.S. B-47 bomber accidentally drops an atom bomb on Mars Bluff, South Carolina. Without a fissile warhead, its conventional explosives destroy a house and injure several people. March 17 – The United States launches the Vanguard 1 satellite. March 19 – The Monarch Underwear Company fire occurs in New York, United States, killing 24 people. March 25 – Canada's Avro Arrow makes its maiden flight. March 26 The United States Army launches Explorer 3. The 30th Academy Awards Ceremony takes place; The Bridge on the River Kwai wins 7 awards, including Academy Award for Best Picture. March 27 – Nikita Khrushchev becomes Premier of the Soviet Union. April April 3 – In Cuba, Castro's revolutionary army begins its attacks on Havana. April 13 – The satellite Sputnik 2 (launched November 3, 1957) disintegrates during reentry from orbit. April 14 – Van Cliburn wins the International Tchaikovsky Competition for pianists in Moscow, breaking Cold War tensions. April 17 – King Baudouin of Belgium officially opens the world's fair in Brussels, also known as Expo 58. The Atomium forms the centrepiece. April 20 – The Montreal Canadiens win the Stanley Cup in ice hockey, after defeating the US team the Boston Bruins in 6 games. April 21 – United Airlines Flight 736 is involved in a mid-air collision with a U.S. Air Force F-100F jet fighter in what is now Enterprise, Nevada; all 49 persons in both aircraft are killed. May May 1 Arturo Frondizi becomes President of Argentina. U.S. space scientist James van Allen announces the discovery of Earth's magnetosphere. The Nordic Passport Union comes into force. May 10 – Interviewed in the Chave d'Ouro café, when asked about his rival António de Oliveira Salazar, Humberto Delgado utters one of the most famous comments in Portuguese political history: "Obviamente, demito-o! (Obviously, I'll sack him!)". May 12 – A formal North American Aerospace Defense Command agreement is signed between the