U.S. bank officials say they're getting little guidance from the Treasury Department, the Federal Reserve or other regulators as they map out how to deal with a possible downgrade in U.S. Treasury securities and default on the country's debt. The nation's largest banks are spending hundreds of hours on contingency planning scenarios to prepare for the possibility that Congress won't raise the federal government's $14.29 trillion borrowing limit by the Aug. 2 deadline. Treasury Department officials warn that without an increased debt ceiling, the government will run out of cash to pay all its bills.