Editing April 22 (section)

===1901–present===
*[[1906]] &ndash; The [[1906 Intercalated Games]] open in [[Athens]].<ref>{{cite book|last=Weed|first=Mike|title=Olympic Tourism|location=Oxford, UK|publisher=Butterworth-Heinemann|date=2008|isbn=978-0-7506-8161-2|url=https://books.google.com/books?id=EGzEDXZYbZwC|page=157}}</ref>
*[[1915]] &ndash; [[World War I]]: The use of [[poison gas in World War I]] escalates when [[chlorine|chlorine gas]] is released as a [[Chemical warfare|chemical weapon]] in the [[Second Battle of Ypres]].
*[[1930]] &ndash; The United Kingdom, Japan and the United States sign the [[London Naval Treaty]] regulating [[submarine]] warfare and limiting [[shipbuilding]].
*[[1944]] &ndash; The [[1st Air Commando Group]] using [[Sikorsky R-4]] helicopters stage the first use of helicopters in [[military helicopter|combat]] with [[combat search and rescue]] operations in the [[China Burma India Theater]].
*  1944   &ndash; [[World War II]]: [[Operation Persecution]] is initiated: [[Allies of World War II|Allied]] forces land in the [[Jayapura|Hollandia]] (currently known as Jayapura) area of [[New Guinea]].
*  1944   &ndash; World War II: In [[Greenland in World War II|Greenland]], the Allied Sledge Patrol attack the German ''Bassgeiger'' [[North Atlantic weather war|weather station]].<ref>{{Cite book|title=War North of 80: The Last German Arctic Weather Station of World War II|last=Dege|first=Wilhelm|year=2004}}</ref>
*[[1945]] &ndash; World War II: Prisoners at the [[Jasenovac concentration camp]] revolt. Five hundred twenty are killed and around eighty escape.
*  1945   &ndash; World War II: [[Sachsenhausen concentration camp]] is liberated by soldiers of the [[Red Army]] and [[Polish First Army]].<ref>{{Cite web|title=Sachsenhausen (Oranienburg): History & Overview|url=https://www.jewishvirtuallibrary.org/history-and-overview-of-sachsenhausen-oranienburg-concentration-camp|access-date=2022-09-27|website=jewishvirtuallibrary.org|publisher=[[Jewish Virtual Library]]}}</ref>
*[[1948]] &ndash; [[1948 Arab–Israeli War|Arab–Israeli War]]: The port city of [[Haifa]] is [[Battle of Haifa (1948)|captured by Jewish forces]].
*[[1951]] &ndash; [[Korean War]]: The Chinese [[People's Volunteer Army]] begin assaulting positions defended by the [[Royal Australian Regiment]] and the [[Princess Patricia's Canadian Light Infantry]] at the [[Battle of Kapyong]].
*[[1954]] &ndash; [[McCarthyism|Red Scare]]: Witnesses begin testifying and live television coverage of the [[Army–McCarthy hearings]] begins.
*[[1966]] &ndash; [[American Flyers Airline Flight 280/D]] crashes on approach to [[Ardmore Municipal Airport]] in [[Ardmore, Oklahoma]], killing 83.<ref>{{Cite web |title=Crash of a Lockheed L-188C Electra in Ardmore: 83 killed |url=http://www.baaa-acro.com/crash/crash-lockheed-l-188c-electra-ardmore-83-killed |access-date=2020-11-23 |website=www.baaa-acro.com |publisher=Bureau of Aircraft Accidents Archives}}</ref>
*[[1969]] &ndash; British yachtsman Sir [[Robin Knox-Johnston]] wins the [[Sunday Times Golden Globe Race|''Sunday Times'' Golden Globe Race]] and completes the first solo non-stop circumnavigation of the world.
*  1969   &ndash; The formation of the [[Communist Party of India (Marxist–Leninist)]] is announced at a mass rally in Calcutta.
*[[1970]] &ndash; The first [[Earth Day]] is celebrated.<ref>{{cite book|last=Mink|first=Nicolaas|chapter=Earth Day|title=Culture Wars: An Encyclopedia of Issues, Viewpoints, and Voices|editor-last=Chapman|editor-first=Roger|location=Armonk, N.Y.|publisher=M.E. Sharpe|date=2010|isbn=9780765617613|url=https://books.google.com/books?id=vRY27FkGJAUC|page=148}}</ref>
*1970 &ndash; Chicano residents in [[San Diego|San Diego, California]] occupy a site under the [[San Diego–Coronado Bridge|Coronado Bridge]], leading to the creation of [[Chicano Park]].<ref>{{cite web |title=Chicano Park: El Parque Chicano |url=https://chicanoparkmuseum.org/logan-heights-archival-project/chicano-park/ |access-date=2023-04-24 |website=Chicano Park Museum and Cultural Center |date=22 April 2016 |language=en-US}}</ref>
*[[1974]] &ndash; [[Pan Am Flight 812]] crashes on approach to [[Ngurah Rai International Airport]] in [[Denpasar]], [[Bali]], Indonesia, killing all 107 people on board.<ref>{{Cite web|last=Ranter|first=Harro|title=ASN Aircraft accident Boeing 707-321B N446PA Denpasar|url=https://aviation-safety.net/database/record.php?id=19740422-0|access-date=2021-04-21|website=aviation-safety.net|publisher=[[Aviation Safety Network]]}}</ref>
*[[1977]] &ndash; [[Optical fiber]] is first used to carry live telephone traffic.
*[[1992]] &ndash; A series of [[gas explosion]]s [[1992 Guadalajara explosions|rip through the streets]] in [[Guadalajara]], Mexico, killing 206.<ref>{{Cite web|date=1992-04-23|title=Guadalajara Gas Blasts Kill 162 : Mexico: A daylong series of explosions thunders under the city, leveling houses and ripping open streets. More than 800 are injured. The cause is disputed.|url=https://www.latimes.com/archives/la-xpm-1992-04-23-mn-1280-story.html|access-date=2021-05-17|website=Los Angeles Times|language=en-US}}</ref>
*[[1993]] &ndash; Eighteen-year-old [[Murder of Stephen Lawrence|Stephen Lawrence]] is murdered in a racially motivated attack while waiting for a bus in [[Well Hall]], [[Eltham]].<ref>{{Cite web |last1=Laville |first1=Sandra |last2=Dodd |first2=Vikram |date=15 November 2011 |title=Stephen Lawrence killed because of 'the colour of his skin' |url=https://www.theguardian.com/uk/2011/nov/16/stephen-lawrence-murder-trial |url-status=live |archive-url=https://web.archive.org/web/20230806201217/https://www.theguardian.com/uk/2011/nov/16/stephen-lawrence-murder-trial |archive-date=6 August 2023 |access-date=6 August 2023 |website=[[The Guardian]]}}</ref>
*[[2005]] &ndash; Japan's Prime Minister [[Junichiro Koizumi]] [[List of war apology statements issued by Japan#2000s|apologizes]] for Japan's war record.
*[[2016]] &ndash; The [[Paris Agreement]] is signed, an agreement to help fight global warming.
*[[2020]] &ndash; Four police officers are [[2020 Eastern Freeway truck crash|killed after being struck by a truck]] on the [[Eastern Freeway (Melbourne)|Eastern Freeway]] in [[Melbourne]] while speaking to a speeding driver, marking the largest loss of police lives in [[Victoria Police]] history.<ref>{{Cite news |date=2020-04-23 |title=How one crash claimed the lives of four police officers on Melbourne's busy Eastern Freeway |language=en-AU |work=ABC News |url=https://www.abc.net.au/news/2020-04-23/how-melbourne-police-crash-unfolded-eastern-freeway/12175770 |access-date=2022-03-15}}</ref>