Berlin Wall Tunnel After Germany was defeated in World War II, it was divided into two sectors. The western part became West Germany, and the eastern part became the Soviet-controlled German Democratic Republic (GDR), or East Germany. Although Berlin was entirely inside East Germany, the city was also divided, with East Berlin becoming the capital of East Germany and West Berlin becoming part of West Germany. In 1961, East Germany erected a wall between East and West Berlin to prevent residents from defecting, or escaping, from East Germany's oppressive communist regime. Concerned about family and friends stuck in East Berlin, a group of West Berlin students came up with a plan. After setting up camp in an abandoned bakery, they spent five months excavating a secret tunnel that wound its way under the wall to an East Berlin apartment building. The students instructed their loved ones in East Berlin to come to the apartment building and gain entrance with a special code word. The rescuers crawled through the tunnel, met the escapees, and guided them to freedom. What is the main idea of the passage?