Attorney General John Ashcroft warned U.S. law enforcement authorities and Americans today to be on heightened vigilance for terrorism and to report anything suspicious. Local police, banks, oil and gas firms, shipping companies and nuclear facilities have all been put on the highest state of alert. Minnesota Congressman Jim Oberstar is the ranking Democrat on the Transportation Committee in the House. He says it will be challenging to monitor all of the nation's waterways, roads, bridges and rails.