The potential damage to oil platforms, refineries and pipelines that remain closed along the Gulf Coast drove energy prices to new highs. Gas prices in the Milwaukee, Wisc. area have risen more than 60 cents a gallon at some locations since Hurricane Katrina struck on Monday. Crude oil prices dropped Wednesday after the U.S. government's decision to make petroleum available from its strategic reserve. Before the announcement, prices had surged above $70 a barrel on growing recognition of the extensive damage to oil platforms and refineries in the Gulf of Mexico.