3. Why did Vladek and his family hide his grandparents? What eventually happened to the grandparents?

The Germans announce that all the elderly are to be shipped off to Theresienstadt, Czechoslovakia. They make it sound like the place is a pleasant retirement home but Vladek and his wife’s family, the Zylberbergs, know better. They hide the grandparents but are forced to give them over when the German's threaten to kill everybody if they are not found. They would be killed.