In Night by Elie Wiesel, Akiba Drumer is selected for extermination. He has given up hope and feels like he can no longer go on. His one request to Elie and his friends is that they should say Kaddish for him, "In three days, I shall no longer be here...say the Kaddish for me." (Wiesel 73)
Elie and the others promised him that when they saw the smoke from the chimney, they would gather a minyan (ten men) and remember him in a service where they would say the Kaddish.
However, three days went by, and the men forgot. Why say the prayer for the dead when they had given up on God? Elie no longer believed. Every day, more Jews were taken to the gas chambers to be exterminated. Death had become a part of their every day life, and prayers no longer mattered. All they could do is try to survive at this point. Forgetting the Kaddish demonstrated that what was once very important to them, was no longer important. They felt abandoned by God, and prayer felt useless.