Historical timeline for April 21

Indonesian Navy submarine KRI Nanggala (402) sinks in the Bali Sea during a military drill, killing all 53 on board.

Eight bombs explode at churches, hotels, and other locations in Sri Lanka on Easter Sunday, killing at least 269.

Two trains are involved in a head-on collision near Sloterdijk, Amsterdam, in the Netherlands, killing one person and injuring 116 others.

The controversial Kharkiv Pact (Russian Ukrainian Naval Base for Gas Treaty) is signed in Kharkiv, Ukraine, by Ukrainian president Viktor Yanukovych and Russian president Dmitry Medvedev; it was unilaterally terminated by Russia on March 31, 2014.

Five suicide car bombers target police stations in and around Basra, killing 74 people and wounding 160.

Four people are killed and 75 are injured in a train accident in Jokela, Finland.

The Supreme Court in La Paz, Bolivia, sentences former dictator Luis García Meza to 30 years in jail without parole for murder, theft, fraud and violating the constitution.

Tiananmen Square protests of 1989: In Beijing, around 100,000 students gather in Tiananmen Square to commemorate Chinese reform leader Hu Yaobang.

The Tamil Tigers are blamed for a car bomb that detonates in the Sri Lankan capital city of Colombo, killing 106 people.

The compound of the militant group The Covenant, The Sword, and the Arm of the Lord surrenders to federal authorities in Arkansas after a two-day government siege.

Baseball: Rollie Fingers of the Milwaukee Brewers becomes the first pitcher to record 300 saves.

Annie opens on Broadway.

Vietnam War: President of South Vietnam Nguyễn Văn Thiệu flees Saigon, as Xuân Lộc, the last South Vietnamese outpost blocking a direct North Vietnamese assault on Saigon, falls.

Astronauts John Young and Charles Duke fly Apollo 16's Apollo Lunar Module to the Moon's surface, the fifth NASA Apollo Program crewed lunar landing.

A tornado outbreak in Illinois, United States, kills over 50 and injures over 1,000. Belvidere sustains over 500 casualties as a violent tornado strikes the high school. Another tornado near Chicago causes another 500 casualties, devastating Oak Lawn.

A few days before the general election in Greece, Colonel George Papadopoulos leads a coup d'état, establishing a military regime that lasts for seven years.

Rastafari movement: Haile Selassie of Ethiopia visits Jamaica, an event now celebrated as Grounation Day.

The 1964–1965 New York World's Fair opens for its second and final season.

A Transit-5bn satellite fails to reach orbit after launch; as it re-enters the atmosphere, 2.1 pounds (0.95 kg) of radioactive plutonium in its SNAP RTG power source is widely dispersed.

The first election of the Universal House of Justice is held, marking its establishment as the supreme governing institution of the Baháʼí Faith.