NEW YORK, "Northwest Airlines Corp. the nation's No. 4 air carrier, on Thursday posted a second-quarter loss, blaming the slump in lucrative business travel and high fuel costs, and said it would cut costs. Northwest Airlines, based in St. Paul, Minnesota, posted a loss of $55 million or 65 cents a share compared with a profit of $115 million or $1.26 a share a year earlier. Wall Street analysts polled...