When exterminating Jews one by one became too inefficient, the Nazis mobilized their victims instead. Trains became one of the essential components of the Nazis’ Final Solution.

By historical estimates, more than three million Jews were taken to their deaths by train. More than 30,000 railcars were involved in that effort, and most trains had up to 50 cars each, with each car holding anywhere from 50 to 200 people.

In winter, occupants were exposed to freezing temperatures. In summer, they endured suffocating heat and stench. There was little or no food, and sanitary conditions were extreme, with a single bucket provided as a toilet. Trips sometimes took days to complete, and many occupants died en route to the camps. Henry Aizenman recalls that cars were so crowded that the dead remained standing, unknowingly held upright by the living.

“But as horrible as that train ride was, at least families were together. For many people, it was the last time they would see their parents, children, brothers, and sisters.”