2014: Three people are killed and 62 injured in a pair of bombings on buses in Nairobi, Kenya.
2007: Greensburg, Kansas is almost completely destroyed by a 1.7 mi wide EF5 tornado. It was the first-ever tornado to be rated as such with the new Enhanced Fujita scale.
1998: A federal judge in Sacramento, California, gives "Unabomber" Theodore Kaczynski four life sentences plus 30 years after Kaczynski accepts a plea agreement sparing him from the death penalty.
1990: Latvia proclaims the renewal of its independence after the Soviet occupation.
1989: Iran-Contra affair: Former White House aide Oliver North is convicted of three crimes and acquitted of nine other charges; the convictions are later overturned on appeal.
1972: The Don't Make A Wave Committee, a fledgling environmental organization founded in Canada in 1971, officially changes its name to "Greenpeace Foundation".
1961: Malcolm Ross and Victor Prather attain a new altitude record for manned balloon flight ascending in the Strato-Lab V open gondola to 113,740 feet (34.67 km).
1949: The entire Torino football team (except for two players who did not take the trip: Sauro Tomà, due to an injury and Renato Gandolfi, because of coach request) is killed in a plane crash.
1942: World War II: The Battle of the Coral Sea begins with an attack by aircraft from the United States aircraft carrier USS Yorktown on Japanese naval forces at Tulagi Island in the Solomon Islands. The Japanese forces had invaded Tulagi the day before.
1932: In Atlanta, mobster Al Capone begins serving an eleven-year prison sentence for tax evasion.
1904: The United States begins construction of the Panama Canal.
1886: Haymarket affair: A bomb is thrown at policemen trying to break up a labor rally in Chicago, United States, killing eight and wounding 60. The police fire into the crowd.
1871: The National Association, the first professional baseball league, opens its first season in Fort Wayne, Indiana.