A crowd of thousands of cheering Germans recreated the historical moment the Berlin Wall came crashing down -- toppling 1,000 graffiti-adorned 8-foot-tall dominoes that fell along the route of the now vanished Cold War icon, celebrating 20 years of freedom from separation and fear.
The spectacle -- billed by organizers as a metaphor for the way the real wall came down 20 years ago Monday and the resulting fall of communist countries in eastern Europe -- was one of several events to mark the anniversary and celebrate the profound change it had not only Germany, but Europe and the world.
Chancellor Angela Merkel -- the first east German to hold the job -- called the fall of the wall an "epic" moment in history.
"For me, it was one of the happiest moments of my life," Merkel said.
Yet she also recalled the tragic side of Nov. 9 for Germans -- the Nazi's Kristallnacht -- or Night of Broken Glass -- anti-Semitic pogrom 71 years ago. At least 91 German Jews were killed, hundreds of synagogues destroyed, and thousands of Jewish businesses vandalized and looted in the state-sanctioned riots that night.
"Both show that freedom is not self evident," Merkel said. "Freedom must be fought for. Freedom must be defended time and again. Freedom is the most valuable commodity in our political and social system."
Earlier, Merkel and former Soviet leader Mikhail Gorbachev crossed a former fortified border on Monday to cheers of "Gorby! Gorby!" as a throng of grateful Germans recalled the night 20 years ago that the Berlin Wall gave way to their desire for freedom and unity.
Within hours of a confused announcement on Nov. 9, 1989 that East Germany was lifting travel restrictions, hundreds of people streamed into the enclave that was West Berlin, marking a pivotal moment in the collapse of communism in Europe.
Merkel, who was one of thousands to cross that night, recalled that "before the joy of freedom came, many people suffered."
She lauded Gorbachev, with whom she shared an umbrella amid a crush of hundreds, eager for a glimpse of the man many still consider a hero for his role in pushing reform in the Soviet Union.
"We always knew that something had to happen there so that more could change here," she said.
"You made this possible -- you courageously let things happen, and that was much more than we could expect," she told Gorbachev in front of several hundred people gathered in light drizzle on the bridge over railway lines.
Tears sprang to the eyes of Uwe Kross, a 65-year-old retiree, who recalled seeing the start of the drama on Nov. 9, 1989 from his home, a block away from the bridge.
"That night, you couldn't stop people," Kross said. "They lifted the barrier and everyone poured through.
"We saw it first on TV, normally it was very quiet up here, but that night we could hear the footsteps of those crossing, tap, tap, tap."
Kross was among those who crossed early on -- so early that nobody was yet waiting on the other side when they reached the West. He recalled hopping on the first subway to then-West Berlin's main boulevard, the Kurfuerstendamm.
"All hell was breaking loose there," Kross said.
Merkel also welcomed Poland's 1980s pro-democracy leader, Lech Walesa, to the former crossing, saying that his Solidarity movement provided "incredible encouragement" to East Germans.
The leaders were joined by prominent former East Germans such as Joachim Gauck, an ex-pastor who later oversaw the archives of East Germany's secret police, the Stasi.
"Those in government thought they were opening a valve, but once it was open much more happened," Gauck said of the border opening. "A collapse followed."
The bridge crossing was one of a series of events marking Monday's anniversary of the border's opening after the wall kept East German citizens penned in for 28 years.
Music from Bon Jovi and Beethoven recalled the joy of the border's opening, which led to German reunification less than a year later and the swift demolition of most of the wall -- which snaked for 96 miles around West Berlin, a capitalist enclave deep inside East Germany.
Memorials were held for the 136 people killed trying to cross the border and candles were lit.
Walesa and Miklos Nemeth, Hungary's last prime minister before communism collapsed, toppled the first wave of the brightly painted and colored dominoes, drawing cheers and applause as they fell upon each other in the cold rain.
Also in Berlin for the ceremonies were the leaders of all 27 European Union countries and Russian President Dmitry Medvedev.
"Naturally, we can't forget that the fall of the wall was prepared by what happened in the Soviet Union," Medvedev said in Russian. "These changes brought advantages to all of Europe ...The Iron Curtain was overcome and the barriers were overcome."
French President Nicolas Sarkozy paid tribute to Berliners on both sides of the wall for realizing the dream of liberty, calling them "Dear Friends" in German.
He recalled that twice in the course of the 20th century, Germans and French stood bitterly pitted against one another, in the course of two tragedies which makes "the peace and liberty of today" all the more joyful.
"We are brothers, we are Berliners," Sarkozy said, echoing the 1963 declaration of President John F. Kennedy.
The wall's opening came hours after a botched announcement by a senior communist official on a cold, wet night in 1989.
At the end of a plodding news conference, Politburo spokesman Guenter Schabowski offhandedly said East Germany was lifting restrictions on travel across its border with West Germany.
Pressed on when the regulation would take effect, he looked down at his notes and stammered: "As far as I know, this enters into force ... this is immediately, without delay."
Schabowski has said he didn't know that the change wasn't supposed to be announced until the following morning.
East Berliners streamed toward border crossings. Facing huge crowds and lacking instructions from above, border guards opened the gates -- and the wall was on its way into history.
Merkel said she was among the East Germans who, hearing Schabowski's words, thought "something might happen on the evening of Nov. 9." Like many others, she made her way across.
By the Brandenburg Gate, the symbol of Germany's division and then of its reunification, which for nearly three decades stood just behind the wall in no man's land, Dieter Mohnka, 74, and his wife Helga, 71, shared a bowl of French fries on Monday afternoon and recalled the night the wall was opened.
"We were shocked when we heard that announced, simply astounded," said Helga. "The next morning we went straight to visit my aunt in the West."
Dieter, a high school teacher at the time, said he had long been fascinated with West Germany.
"I was born in East Germany, I went to school in East Germany. I was supposed to teach the kids about the wonderfulness of the East, when I was secretly watching TV from the West," he said.
"This is not just a day of celebration for Germans," Merkel said. "This is a day of celebration for the whole of Europe; this is a day of celebration for all those people who have more freedom."
The Associated Press contributed to this report.