Detroit to close some schools, convert others to charters 18 Detroit public schools to become charters or be closed 27 more potentially could be converted to charters System has $327 million budget deficit Detroit (CNN) -- As many as 18 Detroit schools will either be converted into charter schools or be closed, Detroit Public Schools Emergency Manager Robert Bobb said Wednesday. Another 27 schools will be offered to anyone that has a plan that meets the public school system's criteria for charter schools. If those schools don't end up as charters, they will remain open. The goal is to eliminate the school system's current $327 million budget deficit, Bobb said. The restructuring reflects the harsh economic reality facing Detroit's schools, which have been hit hard by the recession and decades of decline in the auto industry. "We've done everything we can to right the ship of the Detroit Public Schools," Bobb told CNN in an interview following the press conference announcing the changes. Our city's population is declining, our school population is declining, the number of births in the city in declining and so we have to face the reality that it's not cost-effective to have 300 students in a building that was designed for 1,100 students. The Detroit Federation of Teachers called the plan a "bad idea" in a statement. "This plan is not in the best interests of the taxpayers who own the system, the students and teachers, nor the State of Michigan who will be left holding the bag when we reach the inescapable conclusion that a shrinking school district with a growing deficit cannot survive," the statement read. Bobb acknowledges that the current plan will drive parents and students away from the city's schools, which could worsen the situation. For each student who leaves, the school system loses $7,660 in state aid, according to Stephen Wasko, chief of communications for Detroit Public Schools. The schools identified as potential charter schools are those with a combination of low academic performance, declining enrollment, high operational costs and buildings in poor physical condition, Bobb said at the press conference. Bobb, who was named emergency financial manager of the 87,000-student Detroit Public Schools in 2009, is still working toward a longer-term solution to address the additional schools that need to be closed, he said. The school system is not allowed to declare bankruptcy before Bobb's tenure ends on June 30, Wasko said. CNNMoney's Poppy Harlow contributed to this report