This from Larry Shapiro:
The Countryside FPD responded to a fire in a townhouse at 431 Tyler Court this morning as a crew inside was working on the floors. Evidently vapors ignited creating a flash fire that went out, but not before getting into a void inside the wall between two units. There was no visible sign of fire or damage outside the building, but three units suffered damage as the fire was on two floors and required extensive overhaul to find all of it before it could extend into the attic.
Countryside units were assisted by Lincolnshire-Riverwoods, Mundelein, Lake Zurich, Libertyville, Knollwood, Gurnee, Buffalo Grove, Lake Villa, and Round Lake.
Here are some images from the scene.
A gallery with additional shots is on my site at shapirophotography.net