Sentence:  “So we're talking about <WSD>collateral damage</WSD>?” He hated the expression, because it meant someone took life very lightly, but wasn't that true? That was the nature of murder. "I doubt that poor nurse was the object of our killer's hatred. She was in the wrong place at the wrong time." 
Meaning of the word marked with <WSD> tags:  Unintended victims of an attack targeted at someone or something else.