Washington Metro subway system opens. March 29 – The military dictatorship of General Jorge Videla comes to power in Argentina. March 30 – Land Day: Arab citizens of Israel protest against intended appropriation of land by the government. March 31 – The New Jersey Supreme Court rules that patient in a persistent vegetative state in the Karen Ann Quinlan case can be disconnected from her ventilator. She remains comatose and dies in 1985. March late – The first truly complete recording of the opera Porgy and Bess is released in a 3-LP set, by Decca Records in England and by London Records in the U.S. It stars Willard White and Leona Mitchell. The orchestra is the Cleveland Orchestra conducted by Lorin Maazel. April April 1 Apple Computer Company is formed by Steve Jobs and Steve Wozniak in California. Conrail (Consolidated Rails Corporation) is formed by the U.S. government, to take control of 13 major Northeast Class-1 railroads that have filed for bankruptcy protection. Conrail takes control at midnight, as a government-owned and operated railroad until 1986, when it is sold to the public. The Jovian–Plutonian gravitational effect is first reported by British astronomer Patrick Moore. April 2 – Norodom Sihanouk is forced to resign as Head of State of Kampuchea by the Khmer Rouge led by Pol Pot and is placed under house arrest. April 3 – The Eurovision Song Contest 1976 is won by Brotherhood of Man, representing the United Kingdom, with their song Save Your Kisses for Me. April 5 James Callaghan becomes Prime Minister of the United Kingdom. Tiananmen Incident: Large crowds lay wreaths at Beijing's Monument of the Martyrs to commemorate the death of Premier Zhou Enlai. Poems against the Gang of Four are also displayed, provoking a police crackdown. Segovia prison break: in Spain's largest prison break since the Spanish civil war, 29 political prisoners escape from Segovia prison. April 10 – Frampton Comes Alive!, the multi-platinum selling live album by English rock musician Peter Frampton hits #1 in the Billboard 200 and remains there for 10 weeks, becoming the best-selling album of the year. April 11 – Steve Jobs and Steve Wozniak launch the first Apple computer, the Apple I, for the U.S. hobbyist market. April 13 The Lapua Cartridge Factory explosion in Lapua, Finland kills 40. The United States Treasury Department reintroduces the two-dollar bill as a Federal Reserve Note on Thomas Jefferson's