The Chicago Department of Aviation says more than 500 flights have been canceled at the city's O'Hare International Airport and delays were 90 minutes or more. At Midway International Airport, Southwest Airlines canceled all flights from 10 a.m. Tuesday through 10 a.m. Wednesday and about 10 flights from other airlines also were canceled.
The city of Chicago has put its full fleet of 275 snow plow trucks on the streets.