Z for "Zigeuner" — "Gypsy," then a number. Some survivors still have the horror of the Roma Holocaust tattooed on their skin, a reminder of a lesser-known genocide that researchers are now trying to document.

Rosa Schneeberger is one of the few remaining Sinti, an itinerant community that has been around since medieval times in Western Europe, to have returned from the darkness of the past.

She was only 5 when she was deported with her mother and siblings to the biggest internment camp for Roma in the Third Reich, Lackenbach, which was built in 1940 in Nazi-annexed Austria, and where entire families were subjected to forced labor.