In the United States, each state has their own form of autonomy. Each state has a different approach to issues and problems that may arise. When it comes to pensions each state has the ability to fix any problems with how they handle them. If it requires re budgeting social services, or having to take money from other sources both in state, or from out of state then they do have the ability to do so.
Yes, it is possible for states to fix pension problems, because all they have to do is cut the pensions down. The pensions can start to pay 85 cents on the dollar, or as low as they need to do. This is what would happen in the private sector if a business could not afford to continue to pay a pension.
Many states have overpaid their state workers and have promised many more benefits than they could ever deliver. So now that there is a problem with the economy, they find themselves without pension money because they have used it to pay other bills. It is going to take a lot of juggling and still this might not take care of the problems.
I do not believe it is possible for states to fix pension problems. These pensions were set up at a time when interest rates were much higher and steadier and that simply is not the case now. These pension plans are too expensive and they are not sustainable. There is nothing that can be done to fix something that is simply to expensive.