How does Beth Nimmo use imagery in Rachel's Tears: The Spiritual Journey of Columbine Martyr Rachel Scott?

Imagery:

"When the smoke cleared, twelve young people and one teacher were dead, nearly two dozen more were injured, and hundreds more were traumatized by the hellish sights and sounds they experienced."

"What began as an ordinary school day at our household in a typical middle-class neighborhood just blocks away from Columbine High School gave me no hint of the storm clouds gathering over my home, my family, my city, and ultimately my world"