History of 21 April
- 1992 – Robert Alton Harris became the first person executed by the state of California in 25 years. He was put to death for the 1978 murder of two teen-age boys.
- 1994 – Jackie Parker became the first woman to qualify to fly an F-16 combat plane.
- 1998 – Astronomers announced in Washington that they had discovered possible signs of a new family of planets orbiting a star 220 light-years away.
- 2000 – In Sinking Spring, PA, a man chased his estranged girlfriend through town and then forced her car into the path of an oncoming train. The woman and her 3 passengers were killed.
- 2000 – North Carolina researchers announced that the heart of a 66 million-year-old dinosaur was more like a mammal or bird than that of a reptile.
- 2000 – The 1998 Children’s Online Privacy Protection Act went into effect.
- 2002 – In the city of General Santos, 14 people were killed and 69 were injured in a bomb attack on a department store. The attack was blamed on Muslim extremists.
- 2003 – North and South Korea agreed to hold Cabinet-level talks the following week.
- 2009 – UNESCO launched The World Digital Library. The World Digital Library (WDL) is an international digital library operated by UNESCO and the United States Library of Congress.
- 2012 – Two trains are involved in a head-on collision near Sloterdijk, Amsterdam, in the Netherlands, injuring 116 people.
- 2014 – The American city of Flint, Michigan switches its water source to the Flint River, beginning the ongoing Flint water crisis which has caused lead poisoning in up to 12,000 people, and 15 deaths from Legionnaires disease, ultimately leading to criminal indictments against 15 people, five of whom have been charged with involuntary manslaughter.
- 2019 – Eight bombs explode at churches, hotels, and other locations in Sri Lanka on Easter Sunday, more than 200 people were killed.
Celebration Birthday Today
- 1981 – Mads Junker, Danish footballer
- 1982 – Khalif Barnes, American football player
- 1982 – Micheal Luck, Australian rugby league player
- 1982 – Carnell Williams, American football player
- 1983 – Paweł Brożek, Polish footballer
- 1983 – Marco Donadel, Italian footballer
- 1983 – Tarvaris Jackson, American football player (d. 2020)
- 1984 – Shayna Fox, American voice actress
- 1986 – Audra Cohen, American tennis player
- 1986 – Alexander Edler, Swedish ice hockey player
- 1986 – Rodney Stuckey, American basketball player
- 1986 – Mirko Valdifiori, Italian footballer
- 1987 – Nadif Chowdhury, Bangladeshi cricketer
- 1987 – Eric Devendorf, American basketball player
- 1987 – Leroy George, Dutch footballer
- 1987 – Anastasia Prikhodko, Ukrainian singer
- 1988 – Jencarlos Canela, American singer-songwriter and actor
- 1988 – Pedro Mosquera, Spanish footballer
- 1988 – Adam Rooney, Irish footballer
- 1989 – Tatyana McFadden, Russian-American sprinter and skier
- 1989 – Carlos Muñoz, Chilean footballer
- 1990 – Aleksandar Prijović, Swiss-born Serbian footballer
- 1992 – Isco, Spanish footballer
- 1992 – Rene Santos, Brazilian footballer
- 1992 – Joc Pederson, American baseball player
- 1994 – Mitchell Weiser, German footballer