The blaze started on the roof of a new strip mall at the intersection of 251 and 173 in Machesney Park.
A roofer was taken to Rockford Memorial Hospital for minor burns.
Smoke could be seen for miles and the commotion caused some big time traffic backups along 251. A worker who was inside the building when the fire broke out tells us it didn't take long for the fire to get going.
A new TJ Maxx, Micheals and Office Max is slated for this building, investigators are still trying to determine the cause of the fire.