The Rock Island Fire Marshal tells TV-6 news that the fire that destroyed one building and damaged several others in the downtown district may have been intentionally set and there are persons of interest in the case. Fire officials in Rock Island, IL are investigating a fire that destroyed a downtown building and damaged several surrounding businesses. Crews were called to the 200 block of 18th Street around 4:00 a.m. Saturday, September 27, 2014.