@jonnythan Said
They should have been designed to withstand an impact from an aircraft that didn't even exist?
Before 9/11, no one ever imagined that a plane would be intentionally crashed into a building as a terrorist act. It was just completely off anyone's radar. No one had really ever even considered the possibility.
People don't really think much about the details here. This wasn't an accident. A plane accidentally flying into a building would be going very very slow, in the area of 150-200 mph. The planes that did crash were going closer to 500 mph. That's an impact with
six times the kinetic energy of the accidental scenario.
It's also worth noting that the buildings withstood the impact 100%. The
plane crash didn't bring the buildings down. What brought them down were the massive, multi-floor, jet-fuel powered fires that burned so hot so long it burned away the fire retardant and weakened the steel so much it finally buckled. Remember that these were planes that had just recently taken off for long flights - they were still pretty much at full fuel capacity.
These were truly massive impacts followed by fires of unprecedented size and intensity. The buildings after impact basically consisted of the top portion and bottom portion connected by the damaged, burning part. The damaged, burning part had absolutely no chance of lasting a long time, and once the damaged, burning part failed, the top box fell onto the bottom box. There was zero chance of either box surviving.
There is zero basis to say that any other building would have survived. There was no engineering failure here, of any kind at all. It was something of a triumph that they lasted as long as they did.
I just heard on the news this morning, while waiting in my doctor's office...that the fire burned for 99 days! 99 fricking days to fully extinguish!
That says it all right there.