U.S. industrial production unexpectedly fell in May, likely as a strong dollar and energy spending cuts continued to weigh on manufacturing and mining output, bucking signs of an acceleration in the broader economy. Industrial output fell 0.2 percent after a revised 0.5 percent drop in April, the Federal Reserve said on Monday. The production side of the economy continues to struggle against the lingering effects of dollar strength and deep spending cuts in the energy sector in response to a sharp decline in crude oil prices.