Rather than try to explain myself, this time around I will post a link and a video to explain what is going on. And maybe I'll quote an important part of the article as well:
"US states have spent nearly half a trillion dollars more than they have collected in taxes, and face a $1tn hole in their pension funds, said the CBS programme, apocalyptically titled The Day of Reckoning."Basically this means that over 100 U.S. City Governments are in danger of coming down (i.e. face default) because of a municipal bond crisis. To read the article, click the previous sentence.
"The Day of Reckoning", originally aired on 60 Minutes, came out last week and is available below.