Huge, cheap skate, flimsy, shoddy constructed, hollow shell buildings, but very vulnerable to collapse into a small pile rubble if they have a fire. Those structures were not built to 1910 standards. Before that day, nobody ever saw a building implode because of a fire.
A steel pro that watch the construction said…”Gee, there is practically no steel in this building”. Those buildings were only as strong as the floor boards holding the walls upright. The weak link of the chain.
That’s our economy. A big hollow shell. Vulnerable.