Fear is probably the largest motivation in man's ability to act callousley or even inhumanely towards a fellow human being. In Wiesel's memoir, it does not take terribly long for the less than admirable qualities of being human to emerge.
As the ghetto of Sighet is evacuated and the residents herded aboard a train bound for the concentration camps, one woman, Madame Schater, understands the doom the Jews face. She screams, "Fire! I can see a fire!" Clearly, she is processing the horrors of the ovens that she's heard about, and panicking at the thought of her, and her traveling companion's, fates.
At first, her fellow passengers try to block out her screams and predictions. But when she will not be silenced, they turn on her. Wiesel writes that "the young men tied her up and gagged her. They even struck her...several times on the head -- blows that might have killed her. Her little boy clung to her; he did not cry out...".