 During this period, it was frequently used by homeless persons, who built fires inside for warmth.Reports that homeless people were possibly inside the engulfed warehouse caused fire-rescue personnel to search the six-story building.The searchers' task was made extremely difficult by the large size of the building's interior, the layout, which was a maze of corridors and meat lockers, many with identical flush-handle doors, and the highly flammable composition of its insulation.