why wouldnt they break in half and keel over? If those airliners were able to sever the solid steel core how the hell was the top part able to stay standing for an extra hour? And don't say fire brought it down, open air fires cant reach near the temperatures needed to melt/bend steel. If you've ever made a fire you would know that black smoke (the kind of smoke that erupted from both towers) means the fire is burning weak.