NBC, which hopes to lift its last-place status in the ratings with its coverage of the summer Olympics, got some unsettling news from Nielsen today (Monday). Sunday night's telecast of the U.S. Olympic Trials attracted just 4.48 million viewers, down 20 percent from the comparable Olympic Trials telecast in July four years ago and down 40 percent from the 2008 trials in women's gymnastics on the same night in 2008. It amounted to around half the audience that a rerun of 60 Minutes drew in the same hour and represented even fewer viewers than those who tuned in to ABC's America's Funniest Home Videos in that hour. NBC's own Dateline attracted more viewers at 8 00 p.m., and it was even edged out by a repeat of America's Got Talent , which entered the 10 00 p.m. time period with 4.52 million viewers. Nielsen hastened to note, however, that the figures -- like those of any live event -- are only preliminary and could rise substantially when final national results are announced later today. Moreover, the number of 18-49-year-old viewers that the telecast attracted was substantial, tying it (with Dateline ) for the top ratings of the night in that age group.