For the NYT, this is one of the worst researched articles that I have read in a while. All kinds of relevant information is left out of the article. For instance: How did UA's investments in asset classes differ from the typical pension fund? How did UA's funds perform compared to other plans? How much of the unfunded liability was caused by dramatically higher employee salaries granted around 2000? Was UA contributing sufficient amounts to the funds during the good years?
Anytime the government (not to mention the workers) takes this kind of loss, there should be a serious investigation. Perhaps there were poor (or reckless) investment decisions, perhaps not. This article doesn't really provide any information to judge that.
As for the management fees, $25m/year does strike me as being a little high, but not totally out of line for such a large pension fund. Remember that if you put $6B into average mutual funds, you will be paying about $60m/year in fees. Investment help is not cheap.