Germany is celebrating the 20th anniversary of fall of the world famous Berlin Wall with a number of concerts and memorials being held across the country. Chancellor Angela Merkel is hosting British Prime Minister Gordon Brown, French President Nicolas Sarkozy and Russian president Dmitry Medvedev, besides representatives from the European Union as well as US Secretary of State Hillary Clinton at the Brandenburg Gate, the symbol of German unity. On 9th November, 1989, the communist East German government suddenly opened the border dividing the two Germanies following weeks of pro-democracy protests. Candle lighting and 1,000 towering plastic foam dominoes have been placed along the wall's route and tipped over. A memorial service is also being held for 136 people killed trying to cross over from 1961 to 1989.