Today is International Holocaust Remembrance Day, designated by the United Nations General Assembly to remember the victims killed by Nazi Germany during the Second World War. In commemoration of the day, and in light of recent events, one educator has turned to Twitter to take a look at the terrible story of the MS St. Louis, a refugee ship that saw a number of its passengers killed during the Holocaust after they were turned away from US and Canadian borders prior to World War II. There are many history-related Twitter accounts out there.