CHICAGO (AP) – More than 500 flights were canceled at Chicago’s two international airports and Illinois State Police urged motorists to stay off roads after as much as 4 inches (10.16 centimeters) of wind-blown snow led to whiteout conditions and multiple pileups. More than 380 flights were canceled Thursday at O’Hare International Airport and more than 140 at Midway Airport. The National Weather Service says snow fell at a rate of 1-2 inches per hour and was and blown by winds gusting as high as 40 mph. The Illinois Department of Transportation closed Interstate 39 north of Bloomington Thursday afternoon after state police said a pileup involving approximately 100 vehicles.