The year was highlighted by protests and other unrests that occurred worldwide. Events January–February January – The I'm Backing Britain campaign started spontaneously. January 5 – "Prague Spring": Alexander Dubček is chosen as leader of the Communist Party of Czechoslovakia. January 10 – John Gorton is sworn in as 19th Prime Minister of Australia, taking over from John McEwen after being elected leader of the Liberal Party the previous day, following the disappearance of Harold Holt. Gorton becomes the only Senator to become Prime Minister, though he immediately transfers to the House of Representatives through the 1968 Higgins by-election in Holt's vacant seat. January 15 – The 1968 Belice earthquake in Sicily kills 380 and injures around 1,000. January 21 Vietnam War: Battle of Khe Sanh – One of the most publicized and controversial battles of the war begins, ending on April 8. 1968 Thule Air Base B-52 crash: A U.S. B-52 Stratofortress crashes in Greenland, discharging 4 nuclear bombs. January 23 – North Korea seizes the , claiming the ship violated its territorial waters while spying. January 25 – Israeli submarine sinks in the Mediterranean Sea, killing 69. January 28 – French submarine Minerve sinks in the Mediterranean Sea, killing 52. January 30 – Vietnam War: The Tet Offensive begins as Viet Cong forces launch a series of surprise attacks across South Vietnam. January 31 Viet Cong soldiers attack the Embassy of the United States, Saigon. Nauru president Hammer DeRoburt declares independence from Australia. February 1 Vietnam War: A Viet Cong officer named Nguyễn Văn Lém is executed by Nguyễn Ngọc Loan, a South Vietnamese National Police Chief. The event is photographed by Eddie Adams. The photo makes headlines around the world, eventually winning the 1969 Pulitzer Prize, and sways U.S. public opinion against the war. The Pennsylvania Railroad and the New York Central Railroad merge to form Penn Central, the largest ever corporate merger up to this date. February 6–February 18 – The 1968 Winter Olympics are held in Grenoble, France. February 12 – Vietnam War: Phong Nhị and Phong Nhất massacre. February 24 – Vietnam War: The Tet Offensive is halted; South Vietnam recaptures Huế. February 25 – Vietnam War: Hà My massacre. March–April March 2 – Baggeridge Colliery closes marking the end of over 300 years of coal mining in the Black Country of England. March 6 – Un-recognized Rhodesia executes 3 black citizens, the first