Detroit Free Press Marathon expecting largest turnout in nearly 50-year history

30,00 runners, representing every U.S. state and approximately 30 countries, have signed up for this weekend's Detroit Free Press Marathon. The main race takes the runners over the Ambassador Bridge and back through the Detroit Windsor Tunnel-- the only international under-water mile in any marathon. Vice President and Race Director Aaron Velthoven spoke live with WWJ's Jackie Paige about what to expect. (Photo Credit: Pavel1964/Getty Images).