The Berlin Wall was erected in 1961 by East Germany to prevent mass emigration to West Germany. It separated East and West Berlin and was a heavily fortified concrete barrier with guard towers, barbed wire, mines, and other security measures. Over its 28-year history, nearly 1,000 people died trying to escape from East to West Berlin, by jumping off buildings, drowning, or other means. The wall fell in 1989 amid large protests in East Germany and the relaxation of travel restrictions between East and West Germany, finally allowing reunification in 1990.