BERLIN - Sometimes a mission to do good can land you in a mess.
In 1964, the now silver-haired Berliner Ralph Kabisch and a group of students spent three months digging a tunnel under the Berlin Wall to rescue refugees from the eastern part of the country, in what was perhaps the most militarised city in the world in those days.
They managed to save 57 people through the 145m-long tunnel from Bernauer Strasse in West Berlin to Strelitzer Strasse in East Berlin over two days in October 1964, before they were betrayed.
And their escape through Tunnel 57 is still regarded as one of the most successful in the country.
Lighting was very limited in the 145m-long tunnel. -- PHOTO: RALPH KABISCH
But, the journey was full of unpleasant memories.
Berlin was divided in the 1960s, after a long period of turmoil following World War II that left Western powers controlling West Berlin while the Soviet Union controlled the eastern parts of the city. Over the years, the former came to enjoy a booming economy while many languished in poverty in the latter.
This led to millions fleeing the east for the west. In 1961, East Germany built the wall to close its borders to West Germany.
Many of those who were in the west were tormented by feelings of leaving their kith and kin behind.
A photograph shows the tunnel entrance (Eingang), just in front of the guard post (Postenstand) and the tunnel exit (Tunnel-Ausgang). -- PHOTO: RALPH KABISCH
It was the same with Kabisch too, who was born in East Germany, but had settled in Cologne.
Many of his relatives remained in the east and he was particularly keen to rescue a close cousin, he shares with Thailand's The Nation.
Reporters met Kabisch in Berlin for a video interview on Oct 26, as he and many other Germans prepare to mark 25 years after the fall of Berlin Wall on Nov 9.
Click below to listen to him narrate his story or read on.
In his 20s, Kabisch went to study civil engineering at Berlin University, where he met Wolfgang Fuchs, a prominent German working to rescue people from East Berlin. He soon found himself part of a group of 20 to 25 students who had similar motivations.
But, with the ground water at high levels near the border, there were only two or three spots from where they could do the digging.
Finally, they found an old bakery shop, run by a couple in their 70s, he told The Nation.
Near the bakery's entrance, you could actually see the East German guard towers looming over the wall, says an online article by NPR Berlin news station.
Kabisch rung their bell and requested to rent their basement to use as a dark room to develop photographs.
Tonnes & tonnes of dirt had to be removed with garden spades. -- PHOTO: RALPH KABISCH
The couple agreed. But, the baker soon discovered their hidden motive.
"The baker was surprised but he said I wish you all the best," said Kabisch.
"We worked in groups," he said, explaining that some had to return to university to show that they were still around.
Much of the digging was carried out during the night. -- PHOTO: RALPH KABISCH
"When digging, there were six to eight people on a shift. We had to calculate the volume of soil. The tunnel was 80cm to 1m in diameter.
"First, we were digging a vertical shaft 12m deep and then horizontally.
"After about 10m to 20m of digging, it was quite tough. We had to push the spade with our feet.
"After 10 minutes, we were short of air," he said in the interview, adding that the group brought in a vacuum cleaner and worked on the air direction to allow it to blow in air.
The process took them months. The tunnel was 145m-long.
Many who were rescued were related to the students from West Germany. -- PHOTO: RALPH KABISCH
"We were reaching a part where it suddenly became soft," Kabisch said. "We thought we were very close to the surface. We probably made a mistake in measurement."
"And the soft soil - that happened to be a ditch for a provisional toilet," he added.
Residents of the area built these toilets during those turmoil years, in case their homes were bombed.
"We ended up in s***," said Kabisch, adding, however, that overall it was "positive".
The rescue began after that.
Ordinary swings were used in the tunnel to move people across. -- PHOTO: RALPH KABISCH
One by one the refugees were lined up. Some were children. Others were old.
The two-day operation started in the evening and continued through the dark.
Going through the tunnel made many very nervous. -- PHOTO: RALPH KABISCH
It took people 10 to 15 minutes to go through the tunnel. They had to crawl in the dark.
But someone gave their game away. East Germany's Secret Service detected their hideout.
Did all the rescuers escape? Who gave their game away?
See the video for more.