Social media users posted photos of a plane on fire at the airport, however, an airport spokeswoman said that it is a drill in the burn pit.
At about 3:15 p.m., CFD also tweeted that there is an "active training with live burn" at the airport.
Active training with live burn at O'Hare airport. 4-1-11
— Chicago Fire Media (@CFDMedia) November 27, 2016