The Chicago Teachers Union has filed a lawsuit accusing the city of discriminating against African-American teachers and staff through its effort to reform or shut down local schools. The federal suit says more than half of the tenured teachers who lost their jobs in the most recent wave of school closings were African American, despite African Americans comprising just 30 percent of tenured teachers overall and 35 percent in the under-performing schools that wind up being closed. The teachers’ union is seeking an injunction to stop Chicago Mayor Rahm Emanuel from closing any more schools.