Good Lord, there's a lot of misinformation and stupidity in this thread. It's hard to know where to start. I'll just focus on a few thoughts.
In the first place, not all pension plans are broke or even hopelessly doomed. Most are like social security - overpromised, managed too much for political reasons, with hard choices being avoided. Second, one of the dumbest things you can do is to stop new entrants, because when you do you also stop their contributions to the investment pool. Keeping their contributions moving into the system will help buy time to fix things, so that everyone can receive a secure pension benefit in the long run.
Before someone starts jumping up and down saying "Ponzi scheme", realize that with proper restructuring that most of these plans can be saved. Cut the exorbitant benefits, get rid of the ways to inflate a high-three or high-five salary figure (the number on which pension annuity payments are based), stop or slow the COLA increases after retirement, and raise the funding requirements on both the employee and the employer. If there is no employee contribution required, change that in a hurry. The only way these will work is if there is prescribed funding by both the employee and the employer. In short, create a system based on facts and numbers, not on political pandering.
In drastic cases, you may need to revisit the benefits paid to current retirees. I don't think they have to be walked away from entirely, but those may need to be trimmed. That is only in the worst cases - most plans could be saved with some effort, planning, and hard choices.
There is a lot of hard work needed. Public sector unions will fight this tooth and nail, as will the politicians who are beholden to them. That's a big reason this is a problem in the first place. In my perfect world, we'd get rid of the public sector unions, and fixing the pension systems would be much easier. That's not going to happen, so we need voters to step up and elect people who won't cowtow to public sector and teachers' unions.