The NYT reported that Chicago Mayor Rahm Emanuel is negotiating reductions in pension benefits with the city's workers, including some cuts to retirees. It would have been worth mentioning if the city is also engaged in negotiations with its bondholders to arrange a partial default. Pensions are legal obligations of the city, which enjoy a comparable or higher status than the city's bonds. (In its bankruptcy settlement, Detroit's workers will almost certainly see a higher share of their pension obligations met than its bondholders.)
If Chicago is really unable to meet its pension commitments to retirees, who are now being asked to give back the benefits for which they worked, it would also be reasonable to ask investors to also take some loss. After all, this is what is supposed to happen in a market economy when investors use bad judgement and fail to recognize the risks associated with a loan.