A legacy of generous spending, combined with high unemployment and poor planning, is making the likelihood of U.S. municipal default more likely. Fortune reports that Detroit; Harrisburg, Penn.; and Jefferson County, Ala., are the most likely American municipalities to leave already burdened taxpayers reeling from a growing inability to repay debts.

Detroit's woes are well known. Harrisburg, whose bond-interest payments this year exceed its entire budget, is negotiating with Covanta Holding's (NYSE: CVA) Covanta Energy, the operator of a trash incinerator on which loan payments are being missed. And bungled efforts to refinance bonds in Jefferson County, combined with the inability of troubled guarantor Syncora Holdings to meet its obligations, could force the county into bankruptcy.

Although a Greek-style meltdown is unlikely here, the growing likelihood of defaults is enough to make an already stressed-out and fiscally stretched public even more anxious about prospects for economic recovery. What can municipalities do to get back on track? How much near-term pain will be necessary to achieve long-term gain? Sound off in the comments box below.

Fool online editor Adrian Rush owns no shares of the companies mentioned here. The Fool has a disclosure policy.