by U.S. President Lyndon B. Johnson. 1969 – In Canada, the Official Languages Act comes into force, making French equal to English throughout the Federal government. 1969 – Allegheny Airlines Flight 863 collides in mid-air with a Piper PA-28 Cherokee over Moral Township, Shelby County, Indiana, killing all 83 people on board both aircraft. 1970 – A British airliner is hijacked by the Popular Front for the Liberation of Palestine and flown to Dawson's Field in Jordan. 1971 – The four-day Attica Prison riot begins, eventually resulting in 39 dead, most killed by state troopers retaking the prison. 1972 – In Kentucky's Mammoth Cave National Park, a Cave Research Foundation exploration and mapping team discovers a link between the Mammoth and Flint Ridge cave systems, making it the longest known cave passageway in the world. 1990 – Batticaloa massacre: Massacre of 184 Tamil civilians by the Sri Lankan Army in Batticaloa District. 1991 – Tajikistan declares independence from the Soviet Union. 1993 – Israeli–Palestinian peace process: The Palestine Liberation Organization officially recognizes Israel as a legitimate state. 1994 – Space Shuttle program: Space Shuttle Discovery is launched on STS-64. 2001 – Ahmad Shah Massoud, leader of the Northern Alliance, is assassinated in Afghanistan by two al-Qaeda assassins who claimed to be Arab journalists wanting an interview. 2009 – The Dubai Metro, the first urban train network in the Arabian Peninsula, is ceremonially inaugurated. 2012 – The Indian space agency puts into orbit its heaviest foreign satellite yet, in a streak of 21 consecutive successful PSLV launches. 2012 – A wave of attacks kills more than 100 people and injure 350 others across Iraq. 2015 – Elizabeth II becomes the longest reigning monarch of the United Kingdom. 2016 – The government of North Korea conducts its fifth and reportedly biggest nuclear test. World leaders condemn the act, with South Korea calling it "maniacal recklessness". Births Pre-1600 214/15 – Aurelian, Roman emperor (d. 275) 384 – Honorius, Roman emperor (d. 423) 1349 – Albert III, Duke of Austria (d. 1395) 1427 – Thomas de Ros, 9th Baron de Ros, English soldier and politician (d. 1464) 1466 – Ashikaga Yoshitane, Japanese shōgun (d. 1523) 1558 – Philippe Emmanuel, Duke of Mercœur (d. 1602) 1585 – Cardinal Richelieu, French cardinal and politician (d. 1642) 1601–1900 1629 – Cornelis Tromp, Dutch general (d. 1691) 1700 – Princess Anna Sophie of Schwarzburg-Rudolstadt (d. 1780) 1711 –