theaters. December 13 – King Constantine II of Greece flees the country when his coup attempt fails. December 15 – The Silver Bridge over the Ohio River in Point Pleasant, West Virginia, collapses, killing 46 people. December 17 – Harold Holt, 17th Prime Minister of Australia, disappears when swimming at Cheviot Beach, 60 km from Melbourne. He was briefly replaced as Prime Minister by John McEwen, until the Liberal Party elected Minister for Education and Science John Gorton as leader. December 19 – Professor John Archibald Wheeler coined the astronomical term black hole. December 26 – The Beatles' film Magical Mystery Tour receives its world première on BBC Television in the UK. December 29 – Hyundai Motor founded in South Korea. December 31 The Green Bay Packers become the first team in the modern era to win their third consecutive NFL Championship. They defeat the Dallas Cowboys 21-17 in what becomes known as "The Ice Bowl". Motorcycle daredevil Evel Knievel attempts to jump 141 feet over the Caesars Palace Fountains on the Las Vegas Strip. Knievel crashes on landing and the accident is caught on film. Date unknown Warner Bros. becomes a wholly owned subsidiary of Seven Arts Productions, thus becoming Warner Bros.-Seven Arts. The Jari project begins in the Amazon. Albania is officially declared an atheist state by its leader, Enver Hoxha. The University of Winnipeg is founded in Canada. Lonsdaleite (the rarest allotrope of carbon) is first discovered in the Barringer Crater, Arizona. St Christopher's Hospice, the world's first purpose-built secular hospice specialising in palliative care of the terminally ill, is established in South London by Dame Cicely Saunders with the support of Albertine Winner. PAL is first introduced in Germany. Gunsmoke, after 12 seasons and with declining ratings, almost gets cancelled, but protests from viewers, network affiliates and even members of Congress and especially William S. Paley, the head of the network, lead the network to move the series from its longtime late Saturday time slot to early Mondays for the fall—displacing Gilligan's Island, which initially had been renewed for a fourth season but is cancelled instead. Gunsmoke would remain on CBS until 1975. Lech Wałęsa goes to work in Gdańsk shipyards. The Greek military junta exiles Melina Mercouri. Parker Morris Standards become mandatory for all housing built in new towns in the United Kingdom. Sabon typeface, designed by Jan Tschichold, introduced. Gabriel García Márquez's influential novel