2017-04-21

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.