Industrial output in the United States dropped by 1.1 percent for the month of August, the largest decline since the post-Hurricane Katrina period three years ago, according to figures released by the Federal Reserve. Falling motor vehicle production accounted for about half the overall decline, dropping 11.9 percent. Excluding automobiles and auto parts, production fell 0.6 percent, still higher than the overall average of 0.3 percent predicted by industry analysts. Industrial production includes production at U.S. factories, mines, and utilities. Factory output, which accounts for about four-fifths of overall industrial production, fell by 1.0 percent. Production at utilities dropped 3.2 percent, reflecting a cooler-than-usual August. Mining production, which includes oil drilling, fell 0.4 percent, a probable reflection of shutdowns in the Gulf of Mexico during Hurricane Gustav.