As the world gathers to mark the liberation of the Nazi death camp, a survivor walks where his parents perished and tells his story to Neil Tweedie

　　A momentary encounter saved David Herman from the gas chamber. It was April 1944 and the goods wagon in which he had existed for six days was finally at rest.

　　Neither he nor the 3,000 other Jews with him had much idea about their destination. The night was bitterly cold and silent, except for the barking of unseen dogs. Then the door slid back.

　　"Out!" shouted the SS men. "Out, fast!"

　　Nobody moved.

　　Like a flock of sheep terrified by a predator, the old and young, the strong and weak remained huddled together; as if stillness might yet save them. The Germans ordered in men in prison uniform armed with clubs.

　　One shouted: "You are now at Auschwitz-Birkenau."

　　The prisoners lashed out all about them and, finally, the human cargo began to move. Some fell and were crushed by the weight of the panicking mass behind. The thugs were Sonderkommando, inmates who enforced the will of the Germans in exchange for privileges.

　　David Herman was 16 and he was about to see the last of his mother. As she was pushed away from him she said: "I have lived my life but you are young. Take care of yourself."

　　Unlike the naive, she knew what was coming. In a moment she was gone, lost in the throng.

　　A Sonderkommando hissed: "How old are you?"

　　"Sixteen."

　　"Say you are 18 and that you have a trade."

　　It was good advice. David was judged sufficiently old and useful enough to live. Then he was alone again. His mother, father, two brothers and sister had been on the train but were now gone, eaten up by the darkness.

　　Today, he is 77, a father and grandfather, and back at Auschwitz. Grabbing the barbed wire that once imprisoned him, he said: "It is a great achievement to hold this. Once it was electrified. People threw themselves at it when they could bear no more."

　　Mr Herman is one of the survivors attending a ceremony today marking the 60th anniversary of the camp's liberation by Soviet forces.

　　The great and the good will be there, including the presidents of Russia, France and Israel, and the chancellor of Germany. But the world's attention will focus on the survivors, those who escaped the most monstrous killing machine devised by mankind.

　　The snow was a foot deep at Auschwitz-Birkenau yesterday as Mr Herman and two friends, both inmates of the camps, revisited their past.

　　An unrelenting easterly wind penetrated even the thickest clothing as they laboured through the drifts.

　　"It is as unreal today as it was to me then," said Mr Herman.

　　"How could one believe such things were happening? To me it was like a dream. In only a week I had gone from living with my family to living in Auschwitz." The original Auschwitz – Auschwitz I – was a relatively small-scale affair, a proving ground for methods employed on an industrial scale at nearby Birkenau – or Auschwitz II.

　　Birkenau was the real killing factory. Some 1.1 million human beings met their end in this dark corner of southern Poland. The vast majority were Jews, but many others died, condemned by their lack of Aryan perfection – gipsies, homosexuals, Russian PoWs and other "sub-humans".

　　Mr Herman's mother, Rachel, was one of them. As far as he knows, she was sent straight to the gas chamber following her arrival. The old and the young rarely survived initial selection. Any form of weakness spelt death.

　　The SS was only interested in fit adult males and females who might be worked to death in the service of the Reich.

　　Mr Herman has two abiding memories: of his mother's face when he last saw her, and of the great burial pit of the dead when the scale of the slaughter at Birkenau temporarily overwhelmed the capacity of its four crematoria.

　　"There were three beds to each bunk and five people to each bed in the blocks and I chose the top one when I arrived," he explains.

　　"I could look out through a gap in the wood and there was the pit. They had Russian prisoners of war dumping bodies in it, wheeling the corpses in carts. It was a scene from a dream, the worst dream."

　　The Herman family's journey to Auschwitz began in 1939 when Hungary, an ally of Nazi Germany, was allowed by Hitler to annex a portion of eastern Czechoslovakia which now lies in Ukraine. It contained their family home in the town of Mukacevo.

　　The Hermans were wealthy, owning a brick factory established near the town in the 19th century. Mr Herman's father, Hugo, was a farmer.

　　Life for the young David was good. He was nicknamed Babu because, following his birth, his older brother ran down the street proclaiming: "Babu! I have a new babu!"

　　He remembers no anti-Semitism under Czech rule, and his family prospered. But the skies darkened with the arrival of the Hungarians.

　　"They brought in teachers who incited the children to attack the Jewish children. My father protested to the headmaster but he ignored him." In 1943, the 20,000 Jews in the area were herded into a ghetto. The Hermans, who lived in a spacious apartment within its limits, played host to 24 other people.

　　"There were 15 kids in the house. We had the time of our lives living in the loft.

　　"The mothers found it very hard having to share a kitchen but we thought it was great fun. They whispered about dark things but we were too busy to be scared."

　　There would be time enough to be scared. By March 1944, Hungary was under direct German control.

　　Faced with the advance of Soviet armies in the east and the threat of an Anglo-American invasion in the west, the Germans devoted their resources to wiping out the Jews of Hungary.

　　The project resulted in Auschwitz's busiest period.

　　Within three months, 437,000 Hungarian Jews were transported to the camp – three quarters gassed on arrival.

　　The inhabitants of the Mukacevo ghetto were among them.

　　The call to get ready was sudden. SS men flooded the ghetto ordering all families to be ready in half an hour. They were to deposit all valuables and take only one bag each and some cooking utensils. They were going east, the Germans said, to new lands for farming. Then the train came, 30 wagons between two engines. His father was anxious to be on the first train to stake his claim to a decent plot of land.

　　He was reassured by an SS officer visiting the factory that day. He was later identified as Adolf Eichmann, the principal technician of the implementation of the Final Solution.

　　"My mother made sure she had a full range of dishes so that we could eat kosher," said Mr Herman. Such dishes lie in vast piles in the museum at Auschwitz now, a reminder of that cruel fiction.

　　The six days packed into the train wagons were terrible. Everyone had to stand. The suffering for most ended swiftly and terribly in the gas chambers. The Germans used Zyklon B, a cyanide-based fumigant which cuts off the oxygen supply in the blood, suffocating the victim.

　　David Herman did not spend too long in Auschwitz but he remained there long enough to see his father.

　　"It was the second or third day and I was doing the soup run for my hut and there behind the fence in another compound was this man looking at me. He was strange but somehow familiar, and then I realised that he was my father. He was, like me, shaven all over. I had never seen him without a beard.

　　"He looked so sad, and then he raised his hand and gave a little wave. Then a guard pushed him on. I never saw him again."

　　After a few weeks, David was ordered to Buchenwald concentration camp in Germany to join the Nazi slave labour system.

　　He spent the rest of the war trying to stay alive while suffering injury, serious illness and Allied bombing. But he survived, discovering in 1945 that, against all odds, all of his siblings were also alive.

　　Vrumi, the youngest of the four, had jumped from the train and, due to his age, should have been gassed. But an SS officer adopted him as his servant. Mr Herman was, in time, reunited with his sister Manci, who had been taken to Sweden, and the oldest of the children, Szruli.

　　With Vrumi, Mr Herman was eventually taken to Britain. In 1947, Manci visited the two, their first meeting since that night at Auschwitz. It was from Vrumi that Mr Herman learned of his father's death. A few months after his arrival in Auschwitz he had a hernia and, being judged unfit for work, was gassed.

　　Somehow, despite the horrors of his early years, David Herman built a life. He became a designer of fur coats and a successful businessman.

　　Auschwitz may have been liberated but not his mind. "I remember it every night," he says. "It is always there."