April 20th

An explosion on the Deepwater Horizon oil platform, leased by BP, killed 11 workers and began spewing an estimated 200 million gallons of crude into the Gulf of Mexico for nearly three months.

Danica Patrick became the first female winner in IndyCar history by capturing the Indy Japan 300.

14 students (including killers) and 1 teacher killed, 23 others wounded at Columbine High School in Littleton, Colo., in the nation's deadliest school shooting.

The first Cubans sailing to the United States as part of the massive Mariel boatlift reached Florida.

Soviet air defense shoots down Korean Air Lines Flight 902. The Boeing 707's crew had miscalculated their route, taking them into Soviet air space at the height of the Cold War. The jet made an emergency landing on a frozen lake. Two passengers were killed in the incident.

'The Troubles', the Northern Ireland conflict between republican and loyalist paramilitaries, British security forces, and civil rights groups, claims its 1000th victim.

The manned lunar module from Apollo 16 landed on the moon.

The U.S. Supreme Court upheld the use of busing to achieve racial desegregation in schools.

British politician Enoch Powell makes his controversial "Rivers of Blood" speech.

A human organ is surgically replaced for the first time. Romanian surgeon Dan Gavriliu used a section of the stomach to bypass the esophagus.

RCA publicly demonstrated its new electron microscope.

Baseball Hall of Famer Ted Williams made his major league debut with the Boston Red Sox.

Balfour Declaration recognized, makes Palestine a British Mandate.

The Boston Red Sox played their first game at Fenway Park. They beat the N.Y. Highlanders (who in 1913 would become known as the Yankees) 7-6.

Scientists Marie and Pierre Curie isolated the radioactive element radium.

Nazi leader Adolf Hitler was born in Braunau, Austria.

First pasteurization test completed by Frenchmen Louis Pasteur and Claude Bernard.

The first detective story, Edgar Allen Poe's Murders in the Rue Morgue was published.

The Territory of Wisconsin was established by Congress.

Vice President George Clinton, a former New York governor, died at age 73.

France declared war on Austria, marking the start of the French Revolutionary wars.

Ottawa Indian chief Pontiac murdered.