The Congressional Budget Office discusses the problem here. Where I live, the source of the problem is pretty obvious. The Washington Post editorializes,

Since salaries and benefits amount to 80 percent of county spending – and almost 90 percent of school spending – the fruit of the county’s profligacy is a structural deficit that has proved impervious to repeated tax increases.

The school budget is bloated by overly generous pensions and a high ratio of non-teaching staff to teachers. To the extent that other state and local governments are in trouble for similar reasons, I think that the solution is conceptually simple: stop the looting by public employee unions.