Germans from both sides of the former Berlin Wall celebrated on Monday, 20 years after the Iron Curtain fell, sending East Germans flooding west and setting in motion events that soon led to the country's reunification.

Chancellor Angela Merkel — reunited Germany's first leader to grow up in the communist east — started the day with President Horst Koehler and other leaders at a prayer service at a former East Berlin church that was a rallying point for opposition activists in 1989.

Memorials also were planned to the 136 people killed trying to cross the border. Candles were lit and 1,000 towering plastic foam dominoes placed along the wall's route to be tipped over.

Also expected in Berlin for the ceremonies were the leaders of all 27 European Union countries and Russian President Dmitri Medvedev.