Max Pearson presents a collection of this week’s Witness History episodes from the BBC World Service. This week, we hear from Lumepa Hald who survived the devastating tsunami that hit Samoa in 2009 but suffered a tragic loss. Our expert guest, Prof Tiziana Rossetto, looks back at some of the worst tsunamis in history and how they have shaped our landscapes. Plus we talk to Caster Semenya, the gold medallist who faced questions over her gender at the 2009 World Championships in Berlin. There’s also an interview with Peter Greste, one of three Al Jazeera journalists sentenced to seven years in jail in Egypt. We also look at the mystery surrounding the death of Chilean poet Pablo Neruda with his driver, Manuel Araya. And finally we talk to singer Dafydd Iwan, the “bad boy of Welsh politics”, who was arrested for defacing an English sign. He wanted official recognition for the Welsh language. Contributors: Lumepa Hald – survivor of the tsunami that hit Samoa in 2009. Tiziana Rossetto - Professor of Earthquake Engineering at University College London, UK. Caster Semenya – world champion runner who faced questions over her gender. Peter Greste – journalist sentenced to seven years in prison in Egypt. Manuel Araya – driver of Chilean poet Pablo Neruda. Dafydd Iwan – singer who campaigned for official recognition the Welsh language. (Photo: Devastation at a beach in Samoa after the 2009 tsunami. Credit: Getty Images)