13-year-old Rudolph Goldberg and his brother fled Nazi Germany in 1939, the parents and family they left behind were murdered in the Holocaust.

On the 70th anniversary of the liberation of Auschwitz-Birkenau, 5 live's Adrian Goldberg tells his family story through home recordings of his father. And travelling for the first time to Rudolph's home town, he tries to find out what happened to his relatives.Adrian also hears from those who survived the horrors of Auschwitz and ask how genocide on such a scale could have been allowed to happen.