Artacoma wrote:I work as a construction supervisor and have been a carpenter for 25 yrs. When I use structural steel in a building I have to go to far greater lengths to protect it from fire than I do with structural wood because steel under load simply fails faster than wood in a fire.
Check any building code book.
Agreed,
The impact from something such as a plane is able to dislodge the 'protection' placed around the steel therefor making it much more susceptible to heat than a regular fire in a steel building. It also does not necessarily have to reach melting point for failure to occur, the metal only has to lose about 1/3 of it's strength (the general safety factor placed on most beams and columns).
Wood framing in general will burn very easily, it's the drywall / fire separations that cause the building to take more time to fail under fire. Heavy timber on the other hand can be left unprotected and will take longer than steel to fail.
Concrete is the most dangerous when failing because there is no warning. Steel will buckle and wood will crack but concrete is just there one moment and on your head the next.

(slightly unrelated but if you want a 'fireproof' building concrete is the way to go)