80th anniversary of Auschwitz liberation: survivors return as world remembers Nazi death camp

The Auschwitz-Birkenau death camp – where more than a million Jews were exterminated – has become the ultimate symbol of the holocaust and of Nazi atrocities. Today a museum, it attracts more than two million visitors each year. But 80 years after the camp’s liberation, not all of those visitors treat the site with the reverence it deserves. Report by Adrien Sarlat and Gulliver Cragg.