14 by Bill Haley and His Saddlemen. March 6 – The trial of Julius and Ethel Rosenberg for conspiracy to commit espionage begins in the United States. March 9 – United Artists releases the sci-fi film The Man from Planet X in the United States. March 12 – Hank Ketcham's comic strip Dennis the Menace in the U.S. and Davey Law's Dennis the Menace in the U.K. appear for the first time. March 14 Korean War: Operation Ripper – For the second time, United Nations troops recapture Seoul. West Germany joins UNESCO. March 29 Second Red Scare: Julius and Ethel Rosenberg are convicted of conspiracy to commit espionage. On April 5 they are sentenced to death. Rodgers and Hammerstein's The King and I opens on Broadway, and runs for three years. It is the first of their musicals specifically written for an actress (Gertrude Lawrence). Lawrence is stricken with cancer during the run of the show, and dies halfway through its run a year later. The show makes a star of Yul Brynner. The 23rd Academy Awards Ceremony is held; All About Eve wins the Best Picture award and five others. March 31 – Remington Rand delivers the first UNIVAC I computer to the United States Census Bureau. April April 11 U.S. President Harry S. Truman relieves General Douglas MacArthur of his Far Eastern commands. After its clandestine removal from Westminster Abbey on Christmas Day, 1950, the Stone of Scone resurfaces at Arbroath Abbey in Scotland. April 18 – The Treaty of Paris (1951) is adopted, establishing the European Coal and Steel Community. April 21 – The National Olympic Committee of the Soviet Union is formed. The USSR will first participate in the Olympic Games at Helsinki, Finland, in 1952. April 24 – Sakuragichō train fire: in Yokohama, Japan, a fire on a train kills more than 100. April 27 – RKO releases the Howard Hawks sci-fi film The Thing from Another World. April 28 – 1951 Australian federal election: Robert Menzies' Liberal/Country Coalition Government is re-elected with a decreased majority, defeating the Labor Party, led by former Prime Minister Ben Chifley. Chifley dies a little over a month after the election; he will be replaced by his deputy H. V. Evatt. May May 1 – The opera house of Geneva, Switzerland is almost destroyed in a fire. May 3 King George VI opens the Festival of Britain in London,