Shortly before 5 p.m. CDT on Tuesday, August 28, 1990, Chicago radio stations began announcing the occurrence of tornado deaths in the Plainfield area, some 60 km (40 miles) southwest of the University of Chicago. By 5:30 p.m. the casualty figures were upgraded to 20 deaths and 200 injuries, giving an impression that it was a major tornado event. The path length of the tornado, sketchy in nature at that time, was given as 13 km (8 miles). I called for a project meeting before ending the workday, reaching the conclusion that Duane Stiegler of my staff (15 years of survey experience) should go directly to Chicago's Midway Airport next morning to fly over the entire path. We assumed that the survey would take 2 hours.