KY pension plan is just one of many state, local and municipality pension plan in trouble. Many are underfunded. Part of it is because, politically, it has always been easier to offer more generous retirement benefits vs. higher salaries to public employees. Part of it is 'tale wagging the dog', i.e., politicians can't afford to vote to slash benefits/salaries when it's the public employee union members who've voted them into office. Part of it is the willingness of politicians to accept unnaturally high assumptions regarding investment returns so the required contribution is less. It's a mess that, one day in the near future, is going to bite a whole bunch of folks in the butt. At least a couple of cities in CA have declared bankruptcy in the past few years due, in part, to the exorbitant salaries, benefits, retirement and (especially) retiree healthcare benefits provided.
BTW, studies have cited one of the benefits that public employees enjoy that privates ones don't and it doesn't actually cost the government any cash is the difficulty in firing a public employee. With very few exceptions, job security for public employees is light years better than for private ones.