"We had electricity," Lina said, glad to score a point over him. "We had it in Ember, until it ran out. We had street lights, and lamps in our houses, and electric stoves in the kitchen."
For a moment Torren looked dismayed. "But did you have movies?" He said.
Lina shook her head. "Anyway," she said, "What does all this have to do with my sister?"
"I'm about to tell you, if you'd just let me." The important tone came back into his voice. "So there were all these billions of people, but there got to be too many of them. They messed up the world. That was why the Three Plagues came. But before the Three Plagues, they had the Four Wars."
p. 74-75, The People of Sparks (book two of City of Ember)
The character of Torren goes on to describe the wars were over oil, and religion, and resources. And describes the plagues including, most notably; "....the one where you suddenly can't breathe."
