Fox got “Prison Break” off to a good start last week but viewers’ attention then shifted to Hurricane Katrina and its aftermath, as both the broadcast and cable nets drew large auds for their special coverage.

NBC News’ one-hour “Dateline” spec on Wednesday was primetime’s top-rated program for the week of Aug. 29-Sept. 4 in both adults 25-54 and total viewers (12.18 million), with an ABC News spec on the same night also in the top five, according to Nielsen.

Same nets also shined in their evening news perfs for the frame. NBC’s Brian Williams-anchored “Nightly News” set the pace during the week with an average of 10.58 million viewers (up 31% vs. the previous week), which would have ranked sixth if included among the primetime rankings.

ABC’s “World News Tonight” was a solid second with 9.47 million viewers (up 20% week-to-week), which would have ranked ninth.

Fox News Channel averaged 4.06 million viewers in primetime (up 65% week-to-week) and CNN 3.15 million (up 246%). Third-place news cabler MSNBC drew 1.23 million.

Viewership peaked Thursday, when Fox News averaged 4.83 million in primetime and CNN 3.92 million. By comparison, entertainment skeins on CBS drew 7.41 million, and second-place ABC’s combo of a movie and newsmag drew 5.37 million.

The Aug. 29-Sept. 4 frame also marked the end of the unofficial 14-week summer season, which saw the six broadcast nets combine for a mere 33 share in adults 18-49, down from 39 one year ago, when they benefited from NBC’s coverage of the Summer Olympics.

Overall primetime television usage was virtually unchanged from a year ago, according to Nielsen, with basic cable up 3 shares in 18-49 year-to-year (50 vs. 47) and pay cable down 1 share (6 vs. 7).

ABC’s “Dancing With the Stars” was the summer’s No. 1 series in both 18-49 and total viewers, with Fox also appearing twice among the top five in the demo with newbies “Hell’s Kitchen” and “So You Think You Can Dance.” After “Stars,” the top 10 was all CBS and Fox (see chart).

Looking at the final week of summer, CBS and Fox tied for the lead in adults 18-49 with a 2.3 rating/7 share, with ABC and NBC both at a 2.0/6. The leaders finished in a virtual draw for the summer in this demo, with Fox pulling away in 18-34 and CBS in adults 25-54.

The Eye also swept the summer frames in total viewers.

CBS was paced by Monday repeats of “CSI: Miami” (3.8/10 in 18-49, 11.59 million viewers overall) and “Two and a Half Men” (3.6/9, 10.74m), while unscripted music skein “Rock Star” established highs on both Tuesday (3.2/9, 6.67m) and Wednesday (2.8/8, 6.32m).

Eye devoted less time to Hurricane Katrina than its rivals but popped with a special “48 Hours” on Wednesday at 8 (2.5/8 in 18-49, 8.28m).

At Fox, “Prison Break” (4.6/12 in 18-49, 10.51m) busted out to promising numbers with its two-hour premiere (Daily Variety, Aug. 31) and held up pretty well in its second seg on Monday of the current week (prelim 3.9/9, 8.5 million). Its preem was last week’s No. 1 show in 18-49 and 18-34 (4.8/15).

Net also was solid with Wednesday’s “So You Think You Can Dance” (2.9/9 in 18-49, 7.94m), which held up well on a night when Katrina coverage drew big auds on other nets.

At NBC, Wednesday’s special “Dateline” (3.7/10 in 18-49, 12.18m) dominated the 9 o’clock hour, logging the best demo score for a Peacock series in 12 weeks (“Hit Me Baby One More Time”). Friday’s “Dateline” on the Katrina aftermath also dominated its hour (3.4/11, 10.72m).

“Tommy Lee Goes to College” continues to fade (2.0/5 in 18-49, 4.81m), but the net got a boost Sunday from NASCAR’s “California 500” (3.0/10 in 18-49, 8.45m) — its best showing on the night since May 15.

ABC was propped up by Monday’s Rams-Lions NFL preseason game (3.2/9 in 18-49, 8.63m) and Wednesday’s 10 o’clock news special (3.5/10, 9.34m) but didn’t do much else the rest of the week.

Fox News led the ad-supported cablers for the week in total viewers, but TNT finished on top in adults 18-49 (1.19 rating) thanks to “The Closer” and plays of “Forrest Gump” on Friday, Saturday and Sunday. “Closer” was the week’s top cable program in adults 25-54 (2.1/5).

“Closer” ended its initial season as the year’s most-watched cable series (5.45 million), hitting 6.39 million with its finale on Monday of the current week.

At HBO, week two of “Rome” premiered to an average of 3.03 million viewers on the eve of Labor Day.