NEW YORK: Lights Out

"Who makes hu . . . humidity?" asks a little girl in a current subway advertisement. "Mother Nature," answers the advertiser, New York City's Consolidated Edison electric power company, "... heat, too! And when she combines them for any long stretch—whew! Many thousands of air conditioners run almost constantly, keeping Con Edison electric plants humming. This summer New Yorkers broke all records for the amount of electricity used in a single hour. But it's our job to anticipate your needs . . ."

Con Ed's ad took on dramatic meaning last week when...