Hard to say for sure, but I think the delay was mainly for psychological effect. Seeing the WTC Towers struck by aircraft and on fire is shocking
enough; seeing them fall like that is just traumatic. Literally, massive numbers of Americans suffered from PTSD after 9/11, all across the
country.
I have a personal theory as to why WTC2 fell first but it's just a theory. My idea is that the fire was getting too close to dying out, so they
didn't want to run the risk of having to cover that up. It would be a pretty big problem in their logic (in fact, the darkening smoke is problem
enough). I don't have much to go on, but that's as good as I can do with that question.
I would imagine they could have easily knocked either tower out first without problem in the official line. Think about it..
If WTC1 needed to fall first, they could say it was because it was hit first, obviously.
If WTC2 needed to fall first, they could say it was because of the lower impact point and additional weight those floors would've had to have
held.
The buildings' impact damages coincided so that precisely either of those explanations could have been used. If WTC2 had been impacted higher than
WTC1, for example, the above wouldn't work.
Again, just an idea.





