There are regulations and insurance policies for pensions (PBGC), but they still operate independently and can do very badly if the projections of the costs tha

There are regulations and insurance policies for pensions (PBGC), but they still operate independently and can do very badly if the projections of the costs that were made in 1980s when all these people were promised benefits never grew fast enough or had a few bad investments. The PBGC also only insures a limited portion of the promised benefit, so pensioners benefits usually will get cut either to prevent the fund from failing or it will get cut if it fails and gets taken over by the PBGC.