On April 3

A woman opened fire at YouTube headquarters in San Bruno, California, injuring three people before killing herself.

The northeastern section of Buenos Aires Province, Argentina, experienced several flash floods that killed at least 100 people.

Apple Inc. released the first generation iPad, a tablet computer.

A gunman opened fire at the American Civic Association in Binghamton, New York, U.S., killing thirteen and wounding four before committing suicide.

Texas law enforcement authorities raided the Fundamentalist Church of Jesus Christ of Latter-Day Saints' YFZ Ranch, eventually removing 533 women and children from the premises.

In United States v. Microsoft Corp., Microsoft was found to have violated antitrust law by bundling the web browser Internet Explorer with its Windows operating system.

A U.S. Air Force CT-43 crashed into a mountainside while attempting an instrument approach to Dubrovnik Airport in Croatia, killing all 35 people on board, including Secretary of Commerce Ron Brown.

Aboard Soyuz T-11, Rakesh Sharma became the first Indian to be launched into space.

The Super Outbreak of 148 tornadoes began, killing at least 315 people and injuring 5,484 in 13 US states at the end of a very strong La Niña event.

Luna 10 (replica pictured) entered orbit around the Moon, becoming the first space probe to orbit an astronomical body other than Earth or the Sun.

The Marshall Plan, an economic recovery program established by U.S. Secretary of State George Marshall to assist the post-World War II re-building of Europe, was signed into law.

Philippine resistance against Japan: Cebuano fishermen discovered the Koga papers after a plane crash killed Admiral Mineichi Koga, commander-in-chief of the Imperial Japanese Navy's Combined Fleet.

Lord Clydesdale and David McIntyre undertook the first successful flight over Mount Everest.

Joseph Stalin became the first general secretary of the Communist Party of the Soviet Union.

The libel trial instigated by Irish author Oscar Wilde (pictured) began, eventually resulting in his arrest, trial and imprisonment on charges of gross indecency.

Emma Elizabeth Smith was killed in the first of eleven unsolved murders of women that took place in or near the impoverished Whitechapel district in the East End of London.

The Pony Express, a mail service that became the most direct means of long-distance communication across the United States before the first transcontinental telegraph, began operation.

Robert Walpole took office as First Lord of the Treasury, Chancellor of the Exchequer and Leader of the House of Commons, becoming the first de facto prime minister of Great Britain.

Henry II of France and Philip II of Spain signed the second treaty of Cateau-Cambrésis, ending the Italian War of 1551–1559.

Edward the Confessor, usually considered to be the last king of the House of Wessex, was crowned King of England.