Their city was bombed because they were not able to find Montag, who they believe is a traitor because of his new found adoration for books. Because of this, Montag and other members of the renegade intellectuals set out to rebuild the city.
Montag lived in a world were books and nature was destroyed. People in this millennium find books a taboo. They would rather sit and watch TV. They drive fast and don't care about traffic rules and laws.