By Martin Crutsinger WASHINGTON -- Consumer prices plunged by the largest amount in the past 61 years in October as gasoline pump prices dropped by a record amount. The Labor Department said Wednesday that consumer prices fell by 1% last month, the biggest one-month decline on records that go back to February 1947. The drop was twice as large as the 0.5% decline analysts expected. The big drop reflected not only a huge fall in gasoline and other energy costs, but widespread declines in other areas. Core consumer prices, which exclude food and energy, fell by 0.1% last month, the first drop in core prices in more than a quarter-century. The big retreat in consumer prices reflects a remarkable turnaround from just a few months ago when a relentless surge in energy prices raised concerns that inflation could get out of control. Since that time, the economy has been jolted by the most serious financial crisis in seven decades with all the turbulence expected to push the country into a severe and prolonged recession. The U.S. troubles have quickly spread overseas, depressing growth around the world and cutting into demand for oil and other products, a development that has resulted in sharp declines in the price of crude oil and other commodities. While some are worried that the price retreat could raise the prospect of a deflation, a prolonged bout of falling prices, most economists believe that current conditions are not likely to set the stage for such a development, which last occurred in the U.S. during the Great Depression.