Box 1-4 sent Harrisburg companies to 22 S. 20th Street in Allison Hill for a structure fire around 1345 hours. Chief 7 (Horst) arrived to a working fire in a 2.5 story, occupied, brick, duplex. Squad 8 laid a supply line at Chestnut and S. 20th Streets while Tower 1 took side A in front of the fire building. Heavy fire involved the first floor kitchen and was working its way into the dining room as well as threatening the side D exposure as companies prepared to make an interior attack. The bulk fo the fire was knocked down in about 15 minutes and all searches proved to be negative. The fire building at 22 S. 20th Street suffered heavy fire damage to the first floor and some extension to the second floor all in the rear. The exposure building at 20 S. 20th Street suffered some fire damage to the first floor rear. The attached exposure at 24 S. 20th suffered smoke damage. Box alarm: Squad 8, Wagon 4, Towers 1,3, Chief 7; 1st Alarm: Wagon 3, Tower 2, and Rescue 69, Chief 4 (Hartman), Chief 8 (Snyder).