21 April 1960

The Indonesian Navy submarine Nanggala imploded and sank in the Bali Sea, resulting in the deaths of all 53 people on board.

The city of Flint, Michigan, U.S., changed its water source to the Flint River, which exposed residents to lead poisoning.a

Ukraine and Russia signed the Kharkiv Pact, extending the Russian lease on naval facilities in Crimea.

South Vietnamese president Nguyễn Văn Thiệu resigned on hearing of the fall of Xuân Lộc, the last battle of the Vietnam War.

In response to a dispute over wheat production quotas, Leonard Casley declared his 75 km2 (29 sq mi) farm in Western Australia to be an independent country as the Hutt River Province.

A violent tornado strikes multiple schools and destroys houses in Belvidere, Illinois, United States, causing over 450 casualties.

The Century 21 Exposition, the first world's fair in the United States since World War II, opened in Seattle.

Brasília, a planned city primarily designed by architect and urban planner Lúcio Costa, was officially inaugurated, replacing Rio de Janeiro as the capital of Brazil.

United Airlines Flight 736 collided with a U.S. Air Force fighter jet over southern Nevada, resulting in the deaths of all 49 people on board both aircraft.

Forces of the Republic of Texas led by Sam Houston defeated the Mexican troops of Antonio López de Santa Anna in the Battle of San Jacinto, the decisive and final battle of the Texas Revolution.

The Ladies of Trenton social club hosted a reception for President-elect George Washington as he journeyed to New York City for his first inauguration.

J. S. Bach's cantata Bleib bei uns, denn es will Abend werden, was first performed on Easter Monday.

The Wignacourt Aqueduct (pictured) in Malta was inaugurated, and was used to carry water to Valletta for about 300 years.

Ibrahim Khan Lodi, the last ruler of the Lodi dynasty, was defeated and killed by Babur at the First Battle of Panipat, marking the beginning of Mughal rule in India.

A debt was pardoned by the chief of Tondo on the island of Luzon and recorded on the Laguna Copperplate Inscription, the earliest known calendar-dated document found in the Philippines.

Forces led by Mark Antony fought the Battle of Mutina against those of Decimus Brutus, one of Julius Caesar's assassins.

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.

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.