On this day in history - May 31

What Happened On This Day – May 31

• 2013 The widest tornado ever recorded hits El Reno, Oklahoma

  The storm had a width of 4.2 km (2.6 mi). Nine people were killed as it swept over rural areas of Central Oklahoma.

• 2005 Deep Throat reveals himself

  Former FBI agent Mark Felt admitted that he was the most important informant in the 1970's Watergate scandal which uncovered the dirty tricks of the Nixon administration, ultimately leading to Nixon's resignation.

• 1961 South Africa becomes an independent republic

  Following international criticism of the country's Apartheid regime, it had to leave the Commonwealth of Nations. The system of racial segregation was gradually abolished in the early 1990s.

• 1879 Werner von Siemens presents the world's first electric locomotive

  Von Siemens' landmark invention was soon used in trams. 1881 saw the introduction of the world's first electric tram in Berlin, Germany.

• 1859 The Great Clock housing Big Ben starts keeping time

  The clock at the top of Elizabeth Tower at the north end of the British Houses of Parliament is one of the world's best-known timekeepers.