This from Steve Redick:

This was Sunday morning, 12/9/18.  Some kind of mattress warehouse that was fully sprinklered and metal clad. Initial response was an automatic alarm I believe. Not much to be seen from the outside but got to watch truck 26 do some aggressive ventilation with the aerial as well as some saw work on the side of the building. Here’s a few images and all the rest including video can be seen here:
 
Steve
Chicago FD apparatus at fire scene

Steve Redick photo

smoke from warehouse during a fire

Steve Redick photo

Chicago Firefighters on aerial ladder turntable

Steve Redick photo

Firefighter vents metal clad building

Steve Redick photo

Chicago FD Tower Ladder 14

Steve Redick photo

Chicago FD Engine 95 on a hydrant

Steve Redick photo

Chicago FD MVU 9-

Steve Redick photo