Karen Kratz, a spokeswoman for Nielsen, said she couldn't recall another such occurrence in the roughly 10 years that the company has been releasing weekly ratings information to the press.
"We continue to provide viewer information to our clients (networks, advertisers, etc.), but there simply were not enough programs for the week," Kratz said. "It's also sort of a tribute after all that's happened."
Nielsen does not officially rate any programming block not supported by advertising -- and there were plenty of those during the Sept. 10-16 frame.
The major broadcast networks (ABC, CBS, NBC and Fox) devoted the entirety of primetime on Tuesday, Wednesday, Thursday and Friday to the attacks. Each returned to a semblance of normal programming over the weekend, offering primetime lineups consisting of entertainment shows and one- or two-hour news specials.
Their small rivals, UPN and the WB, aired entertainment programming every night last week except Tuesday, but weekly averages will not be released for them either.
Weekly ratings for the networks' evening news programs also will not be issued, as they aired on Monday only.
Nielsen is scheduled to issue ratings next Tuesday for the week of Sept. 17-23, which becomes the 50th and final week of the 2000-01 television season. The 2001-2002 season kicks off Monday.