A thunderous boom shook the early morning quiet. Orange flame shot into the dark sky as Substation 12 of the Phoenix Grid exploded. Pieces of metal and concrete flew in all directions. The night security guard, having stepped outside for a cigarette moments earlier, stared in shock from the parking lot.

Three blocks away, Rose watched from the passenger seat of a stolen van, her face lit by the distant flames. A small smile played on her lips as smoke rose into the ...