The Nazis used ordinary cattle cars to transport Jews to the hundreds of ghettos, concentration camps and extermination camps they built throughout Europe. People would be packed into the train cars and left, sometimes for days, without food or water. Many people died during these transports. During the winter months, people would freeze, and in summer they asphyxiated. The train cars themselves became instruments of death. Modern historians have suggested that without the mass transportation of the railways, the scale of the Final Solution would not have been possible.