This remarkable memoir by Leon Leyson (born Leib Lejzon) illustrates how tough WWII was for young Jewish boys. 

At just 10 years old, the Nazis raided his new home of Krakow, Poland. He and his family were forced to relocate to a tiny ghetto with terrible conditions. However, with incredible perseverance and with the goal of surviving and reuniting his family, he survived the cruelty of the Nazis, including the diabolic Amon Goeth, the commander of Plaszow (the concentration camp outside Krakow).

The help of one man, the famous Oskar Schindler (who happens to be a Nazi), ultimately saved Leyson's life, along with his mother, father, and siblings.