Host intro: Law enforcement officials around the country have been stepping up security measures everywhere since the September 11 attacks. Officials are operating at a heightened sense of alert even in Duluth, more than a thousand miles from the nearest ocean. Duluth-Superior is the busiest port on the U.S. side of the Great Lakes. Port officials say they are thinking a lot more about security. But they say a terrorist attack on the port is unlikely. Minnesota Public Radio's Stephanie Hemphill has the next report in our series on border security.