Widely known as the “Portuguese Schindler,” Aristides de Sousa Mendes was severely punished by his own government after flouting its neutrality policy with a frantic bid to issue as many visas as possible to desperate refugees fleeing Nazi invasion. In interviews with USC Shoah Foundation, the sons of Sousa Mendes and Jewish survivors rescued by him shared personal stories of his heroism.

Wolf Gruner, the founding director of USC Shoah Foundation’s Center for Advanced Genocide Research, began his quest to build a Holocaust library as part of a new Holocaust program as soon as he arrived at USC via Berlin a decade ago.

Roughly 1,000 audio-only interviews recorded by students of UCLA history Professor Richard Hovannisian were entrusted to USC Shoah Foundation. This week, Hovannisian and three of his former students gave a talk about how they amassed such a large repository of memory at so crucial a time, “when denialism was huge.”

The news about a group of teenagers throwing a Nazi salute at a party in Orange County is a startling reminder that knowledge of the Holocaust is fading. Here are four free online classroom-ready activities on IWitness that address the topics of antisemitism, bystanders and hatred.