5 things to know about the Berlin Wall

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Berlin Wall - updated 11/09/2014
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5 things to know about the Berlin Wall
People watch the release of balloons part of the light installation Lichtgrenze from the former route of the Berlin Wall during a Street Party organized by German governement to mark the 25th anniversary of the fall of the Berlin Wall, in front of the Brandenburg Gate on November 9, 2014 in Berlin. AFP PHOTO / ODD ANDERSEN (Photo credit should read ODD ANDERSEN/AFP/Getty Images)
German singer Udo Lindenberg performs during a Street Party organized by German government to mark the 25th anniversary of the fall of the Berlin Wall, in front of the Brandenburg Gate on November 9, 2014 in Berlin. AFP PHOTO/ ODD ANDERSEN (Photo credit should read ODD ANDERSEN/AFP/Getty Images)
BERLIN, GERMANY - NOVEMBER 09: Fireworks illuminate the Brandenburg Gate during celebrations on the 25th anniversary of the fall of the Berlin Wall on November 9, 2014 in Berlin, Germany. The city of Berlin is commemorating the 25th anniversary of the fall of the Berlin Wall with an installation of 6,800 lamps coupled with illuminated balloons along a 15km route where the Wall once ran and divided the city into capitalist West and communist East. The fall of the Wall on November 9, 1989, was among the most powerful symbols of the revolutions that swept through the communist countries of Eastern Europe and heralded the end of the Cold War. Built by the communist authorities of East Germany in 1961, the Wall prevented East Germans from fleeing west and was equipped with guard towers and deadly traps. (Photo by Sean Gallup/Getty Images)
BERLIN, GERMANY - NOVEMBER 09: Berlin Mayor Klaus Wowereit speaks during celebrations for the 25th anniversary of the fall of the Berlin Wall at the Brandenburg Gate on November 9, 2014 in Berlin, Germany. The city of Berlin is commemorating the 25th anniversary of the fall of the Berlin Wall from November 7-9 with an installation of 6,800 lamps coupled with illuminated balloons along a 15km route where the Wall once ran and divided the city into capitalist West and communist East. The fall of the Wall on November 9, 1989, was among the most powerful symbols of the revolutions that swept through the communist countries of Eastern Europe and heralded the end of the Cold War. Built by the communist authorities of East Germany in 1961, the Wall prevented East Germans from fleeing west and was equipped with guard towers and deadly traps. (Photo by Adam Berry/Getty Images)
German singer Udo Lindenberg performs during a Street Party organized by German government to mark the 25th anniversary of the fall of the Berlin Wall, in front of the Brandenburg Gate on November 9, 2014 in Berlin. AFP PHOTO / ROBERT MICHAEL (Photo credit should read ROBERT MLCHAEL,ROBERT MICHAEL/AFP/Getty Images)
BERLIN, GERMANY - NOVEMBER 09: The Brandenburg Gate stands illuminated during celebrations on the 25th anniversary of the fall of the Berlin Wall on November 9, 2014 in Berlin, Germany. The city of Berlin is commemorating the 25th anniversary of the fall of the Berlin Wall with an installation of 6,800 lamps coupled with illuminated balloons along a 15km route where the Wall once ran and divided the city into capitalist West and communist East. The fall of the Wall on November 9, 1989, was among the most powerful symbols of the revolutions that swept through the communist countries of Eastern Europe and heralded the end of the Cold War. Built by the communist authorities of East Germany in 1961, the Wall prevented East Germans from fleeing west and was equipped with guard towers and deadly traps. (Photo by Sean Gallup/Getty Images)
BERLIN, GERMANY - NOVEMBER 09: Udo Lindenberg performs at the Brandenburg Gate during celebrations on the 25th anniversary of the fall of the Berlin Wall on November 9, 2014 in Berlin, Germany. The city of Berlin is commemorating the 25th anniversary of the fall of the Berlin Wall with an installation of 6,800 lamps coupled with illuminated balloons along a 15km route where the Wall once ran and divided the city into capitalist West and communist East. The fall of the Wall on November 9, 1989, was among the most powerful symbols of the revolutions that swept through the communist countries of Eastern Europe and heralded the end of the Cold War. Built by the communist authorities of East Germany in 1961, the Wall prevented East Germans from fleeing west and was equipped with guard towers and deadly traps. (Photo by Sean Gallup/Getty Images)
BERLIN, GERMANY - NOVEMBER 09: A violinist performs during celebrations for the 25th anniversary of the fall of the Berlin Wall at the Brandenburg Gate on November 9, 2014 in Berlin, Germany. The city of Berlin is commemorating the 25th anniversary of the fall of the Berlin Wall from November 7-9 with an installation of 6,800 lamps coupled with illuminated balloons along a 15km route where the Wall once ran and divided the city into capitalist West and communist East. The fall of the Wall on November 9, 1989, was among the most powerful symbols of the revolutions that swept through the communist countries of Eastern Europe and heralded the end of the Cold War. Built by the communist authorities of East Germany in 1961, the Wall prevented East Germans from fleeing west and was equipped with guard towers and deadly traps. (Photo by Adam Berry/Getty Images)
BERLIN, GERMANY - NOVEMBER 09: Udo Lindenberg performs at the Brandenburg Gate during celebrations on the 25th anniversary of the fall of the Berlin Wall on November 9, 2014 in Berlin, Germany. The city of Berlin is commemorating the 25th anniversary of the fall of the Berlin Wall with an installation of 6,800 lamps coupled with illuminated balloons along a 15km route where the Wall once ran and divided the city into capitalist West and communist East. The fall of the Wall on November 9, 1989, was among the most powerful symbols of the revolutions that swept through the communist countries of Eastern Europe and heralded the end of the Cold War. Built by the communist authorities of East Germany in 1961, the Wall prevented East Germans from fleeing west and was equipped with guard towers and deadly traps. (Photo by Sean Gallup/Getty Images)
Argentinian-born pianist and condutor Daniel Barenboim performs with Staatskapelle during a Street Party organized by German government to mark the 25th anniversary of the fall of the Berlin Wall, in front of the Brandenburg Gate on November 9, 2014 in Berlin. AFP PHOTO / JOHN MACDOUGALL (Photo credit should read JOHN MACDOUGALL/AFP/Getty Images)
BERLIN, GERMANY - NOVEMBER 09: Acrobats swing past the Quadriga statue as they perform over the Brandenburg Gate during celebrations on the 25th anniversary of the fall of the Berlin Wall on November 9, 2014 in Berlin, Germany. The city of Berlin is commemorating the 25th anniversary of the fall of the Berlin Wall with an installation of 6,800 lamps coupled with illuminated balloons along a 15km route where the Wall once ran and divided the city into capitalist West and communist East. The fall of the Wall on November 9, 1989, was among the most powerful symbols of the revolutions that swept through the communist countries of Eastern Europe and heralded the end of the Cold War. Built by the communist authorities of East Germany in 1961, the Wall prevented East Germans from fleeing west and was equipped with guard towers and deadly traps. (Photo by Sean Gallup/Getty Images)
BERLIN, GERMANY - NOVEMBER 09: German President Joachim Gauck (C R), German singer-songwriter and former East German dissident Wolf Biermann (C L) and Polish Solidarity (Solidarnosc) Leader Lech Walesa (R) launch balloons from the Lichtgrenze light installation during celebrations for the 25th anniversary of the fall of the Berlin Wall at the Brandenburg Gate on November 9, 2014 in Berlin, Germany. The city of Berlin is commemorating the 25th anniversary of the fall of the Berlin Wall from November 7-9 with an installation of 6,800 lamps coupled with illuminated balloons along a 15km route where the Wall once ran and divided the city into capitalist West and communist East. The fall of the Wall on November 9, 1989, was among the most powerful symbols of the revolutions that swept through the communist countries of Eastern Europe and heralded the end of the Cold War. Built by the communist authorities of East Germany in 1961, the Wall prevented East Germans from fleeing west and was equipped with guard towers and deadly traps. (Photo by Adam Berry/Getty Images)
Balloons of the light installation Lichtgrenze sail into the night from the former route of the Berlin Wall during a Street Party organized by German governement to mark the 25th anniversary of the fall of the Berlin Wall, in front of the Brandenburg Gate on November 9, 2014 in Berlin. AFP PHOTO / ODD ANDERSEN (Photo credit should read ODD ANDERSEN/AFP/Getty Images)
People watch fireworks after the release of balloons part of the light installation Lichtgrenze from the former route of the Berlin Wall during a Street Party organized by German governement to mark the 25th anniversary of the fall of the Berlin Wall, in front of the Brandenburg Gate on November 9, 2014 in Berlin. AFP PHOTO / ODD ANDERSEN (Photo credit should read ODD ANDERSEN/AFP/Getty Images)
BERLIN, GERMANY - NOVEMBER 08: A visitor peeks into the former 'death strip' between layers of the former Berlin Wall next to a former East German guard tower at the Berlin Wall Memorial at Bernauer Strasse on the day before the 25th anniversary of the fall of the Wall on November 8, 2014 in Berlin, Germany. The city of Berlin is commemorating the 25th anniversary of the fall of the Berlin Wall from November 7-9 with an installation of 6,800 lamps coupled with illuminated balloons along a 15km route where the Wall once ran and divided the city into capitalist West and communist East. The fall of the Wall on November 9, 1989, was among the most powerful symbols of the revolutions that swept through the communist countries of Eastern Europe and heralded the end of the Cold War. Built by the communist authorities of East Germany in 1961, the Wall prevented East Germans from fleeing west and was equipped with guard towers and deadly traps. (Photo by Carsten Koall/Getty Images)
BERLIN, GERMANY - NOVEMBER 08: Former Berlin Wall next to a former East German guard tower at the Berlin Wall Memorial at Bernauer Strasse on the day before the 25th anniversary of the fall of the Wall on November 8, 2014 in Berlin, Germany. The city of Berlin is commemorating the 25th anniversary of the fall of the Berlin Wall from November 7-9 with an installation of 6,800 lamps coupled with illuminated balloons along a 15km route where the Wall once ran and divided the city into capitalist West and communist East. The fall of the Wall on November 9, 1989, was among the most powerful symbols of the revolutions that swept through the communist countries of Eastern Europe and heralded the end of the Cold War. Built by the communist authorities of East Germany in 1961, the Wall prevented East Germans from fleeing west and was equipped with guard towers and deadly traps. (Photo by Carsten Koall/Getty Images)
BERLIN, GERMANY - NOVEMBER 08: Visitors walk under a light installation of balloons tethered to lamps along the course of the former Berlin Wall in Mauerpark a day before the 25th anniversary of the fall of the Wallon November 8, 2014 in Berlin, Germany. The city of Berlin is commemorating the 25th anniversary of the fall of the Berlin Wall from November 7-9 with an installation of 6,800 lamps coupled with illuminated balloons along a 15km route where the Wall once ran and divided the city into capitalist West and communist East. The fall of the Wall on November 9, 1989, was among the most powerful symbols of the revolutions that swept through the communist countries of Eastern Europe and heralded the end of the Cold War. Built by the communist authorities of East Germany in 1961, the Wall prevented East Germans from fleeing west and was equipped with guard towers and deadly traps. (Photo by Carsten Koall/Getty Images)
BERLIN, GERMANY - NOVEMBER 08: Visitors walk under a light installation of balloons tethered to lamps along the course of the former Berlin Wall in Mauerpark a day before the 25th anniversary of the fall of the Wallon November 8, 2014 in Berlin, Germany. The city of Berlin is commemorating the 25th anniversary of the fall of the Berlin Wall from November 7-9 with an installation of 6,800 lamps coupled with illuminated balloons along a 15km route where the Wall once ran and divided the city into capitalist West and communist East. The fall of the Wall on November 9, 1989, was among the most powerful symbols of the revolutions that swept through the communist countries of Eastern Europe and heralded the end of the Cold War. Built by the communist authorities of East Germany in 1961, the Wall prevented East Germans from fleeing west and was equipped with guard towers and deadly traps. (Photo by Carsten Koall/Getty Images)
BERLIN, GERMANY - NOVEMBER 08: Visitors walk under a light installation of balloons tethered to lamps along the course of the former Berlin Wall in Mauerpark a day before the 25th anniversary of the fall of the Wallon November 8, 2014 in Berlin, Germany. The city of Berlin is commemorating the 25th anniversary of the fall of the Berlin Wall from November 7-9 with an installation of 6,800 lamps coupled with illuminated balloons along a 15km route where the Wall once ran and divided the city into capitalist West and communist East. The fall of the Wall on November 9, 1989, was among the most powerful symbols of the revolutions that swept through the communist countries of Eastern Europe and heralded the end of the Cold War. Built by the communist authorities of East Germany in 1961, the Wall prevented East Germans from fleeing west and was equipped with guard towers and deadly traps. (Photo by Carsten Koall/Getty Images)
BERLIN, GERMANY - NOVEMBER 08: Visitors look a documentary about the WAll in Mauerpark a day before the 25th anniversary of the fall of the Wallon November 8, 2014 in Berlin, Germany. The city of Berlin is commemorating the 25th anniversary of the fall of the Berlin Wall from November 7-9 with an installation of 6,800 lamps coupled with illuminated balloons along a 15km route where the Wall once ran and divided the city into capitalist West and communist East. The fall of the Wall on November 9, 1989, was among the most powerful symbols of the revolutions that swept through the communist countries of Eastern Europe and heralded the end of the Cold War. Built by the communist authorities of East Germany in 1961, the Wall prevented East Germans from fleeing west and was equipped with guard towers and deadly traps. (Photo by Carsten Koall/Getty Images)
BERLIN, GERMANY - NOVEMBER 08: Visitors look a documentary about the WAll in Mauerpark a day before the 25th anniversary of the fall of the Wallon November 8, 2014 in Berlin, Germany. The city of Berlin is commemorating the 25th anniversary of the fall of the Berlin Wall from November 7-9 with an installation of 6,800 lamps coupled with illuminated balloons along a 15km route where the Wall once ran and divided the city into capitalist West and communist East. The fall of the Wall on November 9, 1989, was among the most powerful symbols of the revolutions that swept through the communist countries of Eastern Europe and heralded the end of the Cold War. Built by the communist authorities of East Germany in 1961, the Wall prevented East Germans from fleeing west and was equipped with guard towers and deadly traps. (Photo by Carsten Koall/Getty Images)
BERLIN, GERMANY - NOVEMBER 08: Visitors look a documentary about the WAll in Mauerpark a day before the 25th anniversary of the fall of the Wallon November 8, 2014 in Berlin, Germany. The city of Berlin is commemorating the 25th anniversary of the fall of the Berlin Wall from November 7-9 with an installation of 6,800 lamps coupled with illuminated balloons along a 15km route where the Wall once ran and divided the city into capitalist West and communist East. The fall of the Wall on November 9, 1989, was among the most powerful symbols of the revolutions that swept through the communist countries of Eastern Europe and heralded the end of the Cold War. Built by the communist authorities of East Germany in 1961, the Wall prevented East Germans from fleeing west and was equipped with guard towers and deadly traps. (Photo by Carsten Koall/Getty Images)
BERLIN, GERMANY - NOVEMBER 08: Visitors walk under a light installation of balloons tethered to lamps along the course of the former Berlin Wall in Mauerpark a day before the 25th anniversary of the fall of the Wallon November 8, 2014 in Berlin, Germany. The city of Berlin is commemorating the 25th anniversary of the fall of the Berlin Wall from November 7-9 with an installation of 6,800 lamps coupled with illuminated balloons along a 15km route where the Wall once ran and divided the city into capitalist West and communist East. The fall of the Wall on November 9, 1989, was among the most powerful symbols of the revolutions that swept through the communist countries of Eastern Europe and heralded the end of the Cold War. Built by the communist authorities of East Germany in 1961, the Wall prevented East Germans from fleeing west and was equipped with guard towers and deadly traps. (Photo by Carsten Koall/Getty Images)
BERLIN, GERMANY - NOVEMBER 08: Visitors walk under a light installation of balloons tethered to lamps along the course of the former Berlin Wall in Mauerpark a day before the 25th anniversary of the fall of the Wallon November 8, 2014 in Berlin, Germany. The city of Berlin is commemorating the 25th anniversary of the fall of the Berlin Wall from November 7-9 with an installation of 6,800 lamps coupled with illuminated balloons along a 15km route where the Wall once ran and divided the city into capitalist West and communist East. The fall of the Wall on November 9, 1989, was among the most powerful symbols of the revolutions that swept through the communist countries of Eastern Europe and heralded the end of the Cold War. Built by the communist authorities of East Germany in 1961, the Wall prevented East Germans from fleeing west and was equipped with guard towers and deadly traps. (Photo by Carsten Koall/Getty Images)
German singer Udo Lindenberg performs during a Street Party organized by German government to mark the 25th anniversary of the fall of the Berlin Wall, in front of the Brandenburg Gate on November 9, 2014 in Berlin. AFP PHOTO / ROBERT MICHAEL (Photo credit should read ROBERT MLCHAEL,ROBERT MICHAEL/AFP/Getty Images)
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BERLIN (AP) - The Berlin Wall fell 25 years ago on Sunday, a key event in the collapse of communism and the preface to Germany's reunification in 1990.

The anniversary is being celebrated in Berlin with concerts, speeches and the release in the evening of thousands of balloons illuminating a 15-kilometer (nine-mile) stretch of the former Cold War barrier.

Here are five things to know about the Berlin Wall:

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PROTECTION AGAINST 'FASCISM'

At 1 a.m. on Aug. 13, 1961, East Germany sealed off the border between the Soviet-controlled eastern sector of Berlin and the western sectors controlled by the Allies.

Over the following weeks, workers erected a 155-kilometer (96-mile) barrier encircling West Berlin. The Wall itself - up to 3.6 meters (12 feet) high - was merely the outermost part of a heavily fortified strip that variously included barbed wire, metal fences, guard towers, hidden alarms and dog walkways.

Communist leader Walter Ulbricht called it an "anti-fascist protective wall," though in reality its purpose was to stop the flood of people leaving for the West.

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GREAT ESCAPES

Despite the formidable obstacle and threat of stiff punishment if caught, thousands of people tried to escape by tunneling under, swimming past, climbing or flying over the wall.

Many took advantage of Berlin's extensive sewer and subway network. Others used fake passports made out to West Germans, who were allowed to visit East Berlin.

Some dug their own tunnels, often with help from people on the other side. In one case, an entire family escaped using a home-made cable car.

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WALL OF DEATH

At least 136 people, including several children, lost their lives along the Cold War barrier, according to the Potsdam Center for Historical Research.

Some were shot by East German border guards, others drowned in the chilly river Spree.

One of the last to die was Chris Gueffroy. The 20-year-old was shot dead nine months before the fall of the Wall.

Crosses now mark many of the locations where people died trying to reach freedom.

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REAGAN SPEECH

During its 28-year existence, the Wall served as a symbol for communist oppression.

Western leaders, including U.S. President John F. Kennedy, often had a stop at the Wall when they visited Berlin.

The ominous, grey concrete barrier served as the backdrop for U.S. President Ronald Reagan's call in 1987 to then-Soviet leader Mikhail Gorbachev to "tear down this wall!"

Gorbachev later claimed not to have taken the dramatic appeal seriously, calling it a "performance" by the one-time Hollywood actor. But the speech, like Kennedy's famous line about considering himself "a Berliner," helped keep up morale in the western part of the city.

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WALL'S FALL

On the evening of Nov. 9, 1989, West German television broadcast the news that communist authorities had decided to lift travel restrictions and allow East Germans to travel more or less freely.

The reports were based on a confusing announcement by a senior East German official who had failed to spell out various caveats to the new policy. Before the communist authorities could set the record straight, thousands of East Berliners had pushed their way past perplexed border guards to celebrate freedom with their brethren in the West.

The communist dictatorship was swept away within months. On Oct. 3, 1990, East and West Germany became one country again.

25 Years After the Berlin Wall, These Barriers Remain

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