Marathon negotiations began last November, but they broke down yesterday and today some 26,000 teachers are on strike in Chicago. Classes have been cancelled for more than 350,000 students. Rahm Emanuel, President Obama's former chief of staff, is the Mayor who hand-picked the school board. This is the first strike in America's third largest school system in 25 years. Joel Weisman is host of Chicago Week in Review on public television station WTTW, Channel 11.