Is really collapse the the main danger to consider when a fire happens? I would think that when a building collapses from fire, many people in the building would already be dead from smoke and heat. If a wooden building would stand longer but be smoke filled earlier, I am not sure it can be said to be safer.
Everything else around your structural elements are going to be putting out smoke that will kill occupants regardless of whether the structure is steel or wood in situations like this. You worry about collapse for cases when the fire on a lower level traps occupants above, and the more time you can buy to control the fire or evacuate the better.
