What is the climax in Dawn by Elie Wiesel?

The climax occurs when Elisha learns that he is the one selected to execute John Dawson. This is his first face-to-face killing. As he waits for dawn, the time the execution will take place, many thoughts plague him. He struggles with the thought of killing someone, who hasn't done anything to him. He is visited by all the people he has known, who are now dead. One of them even looks like the boy he used to be before the war tore everything apart. He looks for answers from his fellow members, but they only try to comfort him by telling him that it's war.