Whirlpool shares tumbled Thursday after the iconic appliance maker warned that the war in Iran triggered a severe downturn, underscoring how sharply higher fuel prices and collapsing consumer confidence are beginning to weigh on big-ticket purchases. "War in Iran resulted in recession-level industry decline in the U.S. as consumer confidence collapsed in late February and March," the company said in its earnings filing. The comments marked one of the starkest corporate warnings yet about the economic fallout from the conflict and contrasted with more resilient spending trends recently highlighted by companies tied to travel and services. Shares of Whirlpool, maker of washers, dryers, dishwashers and other home appliances, dropped a whopping 20% in premarket trading. Loading chart... CEO Marc Bitzer said Whirlpool moved quickly to cut costs and adjust pricing as macroeconomic conditions deteriorated.…