NEW YORK — The American dream of a blissful retirement, free of financial worries, is dying.Most U.S. households are heading for a worse lifestyle in retirement than they had while they were working, because they simply aren't saving enough, experts say. Thirty-five percent of households in their prime earning years or later have nothing saved in a retirement account and no access to a traditional pension, according to an AP analysis of savings data from the Federal Reserve.Among households that do have some savings, the typical amount is $73,200. That's about 15 months of the median household's income.One group doesn't have to worry as much: the richest 10 percent of households.