It could be due to the fact that most of the actual spreading fire was on the outside of the building. Had the building not been remodeled last year, it would have probably been a minor fire. The environmentally friendly newly installed building cladding seems to be very flammable and had a chimney effect to boot. Sounds like the panels were made of cheap plastic, which doesn't seem like a good idea for siding a high rise. Since the building was built in 1974, I am guessing the exterior was plain ugly concrete before like most public housing of the era.