This Is What It Looks Like When You Shut Down a Major Airport

Hundreds of flights have been canceled to and from O'Hare and Midway airports.

Police said the fire was extinguished but there is an ongoing investigation.

As of 9:05 a.m. ET, reported 446 cancellations to and from O'Hare and Midway airports, 13 percent of their daily schedule, and 107 delays. said the number of cancellations and delays will “rise considerably” over the next few hours.

Contract Employee Eyed in Fire That Grounded Chicago Flights

ABC News' Matt Hosford contributed to this report.