Grandchildren of Holocaust survivors, two generations removed from the Nazis’ horrors, are stepping up to tell the stories of their grandparents, eager to show there are still lessons to learn from the calamitous but increasingly distant years of World War II. They are visiting schools and speaking at community events, as their grandparents did for decades, hoping the world will never forget how the Nazis destroyed their families, their cities and their culture. A school visit by a Holocaust survivor has become a mainstay of South Florida students’ education since Florida mandated Holocaust instruction in 1994. But witnesses to the Holocaust are now mostly gone.