Well apparently you never operated a wood stove or a blacksmith forge , or been a fireman .They use low velocity air to generate steel working temps or in the case of a fireman , a backdraft explosion of intense heat when air is fed to a fire! Many Pans sitting on a burning fire with nothing in them will warp and burn, maybe not melt or burn thru on a propane stove with the temp running about 1250 degrees at the flame but I have many that are warped and wrinkled from camping. If you are a welder as you claim you should understand basic structural properties and steel properties and how heat affects metals / how metals can weaken along side a weld and crack. When you are talking tons of pressure per sq /in it doesn't take much of a damaged structure that was impacted combine with heat for steel to fail to maintain its strength. The dark smoke was from Fuel and rubber compounds burning, and the air intake thru the busted windows allowed the fire to be air fueled thru elevator shafts air ducts , and passageways, The same way a woodstove works , and I can turn 8 inch stovepipe cherry red in about 15 minutes running wide open with spruce or oak wood which burns at a lower temp than jet fuel. Look at how gun fired Fuel oil stoves are lined inside...it sure as hell isnt steel, its a ceramic/ firebrick composition burn chamber and most wood stoves are lined with firebrick for the same reason. The steel walls inside my wood stove are all bent and warped from Heat from just wood burning. If you never saw a fuel tank rupture and catch fire you should watch it sometimes...as the remaining fuel heats it expands and starts spraying fuel like a flamethrower which also forms a torch effect !
Dude, look at the picture I posted of the burned building steel that was only supporting a steel roof that was light weight compared to a building supporting tons above it and burning carpet and air did that.. What I have stated are all facts not conspiracy theories from nutcases or Govt. investigations. I'm a welder, machinist,Gunsmith, Fabricator, Metalworker , blacksmith , and I have built everything from dragsters to Transformer supports for power companies, weapons , stoves, trailers, cannons, drivelines and shafts , as well as working with some renowned scientists on projects , and working with explosives . I think I'm qualified to make an assessment by applying facts and scientific analysis. By the way , I weld fuel tanks with fuel in them when nobody else will !