Preparations are well under way for Berlin's celebration of the 20th anniversary since the fall of the Berlin Wall. Former Chancellor Helmut Kohl, Ex-US President George H. W. Bush and Mikhail Gorbachev are expected for a late October event. On the actual anniversary day, some 1,000 giant foam blocks, brightly painted to recall the graffiti which plastered the west side of the Berlin Wall, will be knocked down between Potsdamer Platz and the Reichstag in the heart of Berlin. Former Solidarity leader Lech Walesa will do the honors. On Wednesday, the first of the completed dominos arrived in Berlin.