BERLIN — Chancellor Angela Merkel thanked former Soviet leader Mikhail Gorbachev for making change possible in East Germany as she visited what was once a fortified border crossing today — retracing her steps on the night 20 years ago the Berlin Wall fell.

The Bornholmer Strasse bridge was the first crossing to open on Nov. 9, 1989, following a confused announcement that East Germany was lifting travel restrictions — a pivotal moment in the collapse of communism in Europe.

Merkel, who grew up in East Germany and was one of thousands to cross that night, recalled that “before the joy of freedom came, many people suffered.”

She lauded Gorbachev 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, winning applause and cheers from a crowd of several hundred people gathered in light drizzle on the bridge over railway lines.

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 bridge crossing was one of a series of events marking today’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 was to recall 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 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 later today.

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

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.

“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.”