Companies were dispatched to 1055 Clifton ave in Darby Twp for the possible kitchen fire. P/D arrived reporting a working fire confirming all occ's were out of the dwelling. 09-1 arrived to heavy fire blowing out all of the 1st floor front windows. They led off with a deck gun. Once the bulk of the fire was knocked companies went to the interior to get to extension they had to the 2nd floor. Truck companies vented windows and the roof, while interior crews opened up walls and cielings for the extension. Crews were in svc with several handlines.