On a Monday morning last November, police in this southern Mexican city received a tip that violent youth gangs, known as maras, were planning to invade a local junior high school to avenge the arrests of 20 of their members in a brawl at a school parade. A patrol car was sent to the school, and within minutes, word of the threat had spread across the city like a brush fire. Thousands of parents, terrified of the tattooed, extremely violent gang members, rushed to pull their children out of class. Most schools in the city of 300,000 abruptly closed, and many stayed shut for a week.Full Story