First due companies found heavy fire venting from the #1 floor on sides 2 and 3 of this 3sty wdfm occupied dwelling. Heavy fire was overlapping on side 2 and up the rear stair well blocking the exit from the upper floors. A second alarm was requested due to the life hazard and fire conditions. Reports of 5 rescues were made with the possibility of a few jumpers from floor 2. Interior crews chased fire from floor 1 into the attic before the all out was given. A third alarm was requested for manpower for overhaul and salvage.