In the first excerpt what do think causes Madame Schachter's terrible visions?

Madame Schacter is a character of the book "Night", written by Elie Wiesel.

On the train to Auschwitz, Elie meets Madame Schacter who has having visions of fire. She constantly warns the people on the train of the flames that awaits them. Her Words prove be true as Elie steps off the train and witnesses the flames of the crematorium and the smell of burning flesh...