There are no "problems" with the collapse. With regard to the towers, the very signs of a fire-induced collapse which David Ray Griffin says would be there in a fire-induced collapse WHERE EVIDENT (he is just ignorant of them or suppresses them) With the towers, we can see inward bowing of exterior load bearing columns well before the collapse. We can see that the inward bowing progressed over time until the point of failure.: https://www.youtube.com/watch?v=sGAoRrBoPRM&list=PL0EA5787F8154537B
The very first video I uploaded to YouTube which should have put an end to David Ray Griffin's ignorant claims several years ago : https://www.youtube.com/watch?v=sGAoRrBoPRM&list=PLfrlsC1yJ2dSIYYEW5LRZx-m25GW9xAps
The very same area that we can see in a photo here: https://sites.google.com/site/representativepress/east-face-of-wtc2-9-21-am
then you can see that the bowing has progressed in a photo here: https://sites.google.com/site/representativepress/east-face-of-wtc2-9-53-am
Then you can see that very same bowed in area where it reaches the point of total failure in this video here: https://www.youtube.com/watch?v=BQmaGCxHxj8
We can see the early stages of the bowing in the two pictures linked above and then we can see how that bowed in area reaches the point of total failure in the video linked above.
All these conspiracies about "controlled demolition" are a misdirection from the MAIN motive for the attack which was anger at US support of Israel. People in positions of power such as journalists, pundits and politicians have suppressed or downplayed or lied about the main motive for the attack. THAT game is what "9/11 Truth" helps by having people fixate on a collapse when the point is WHY was the attack perpetrated and I have show how the two top commissioners admitted that their concern over protecting the the policy of supporting Israel, keeping the public from reevaluating that policy, is what concerned them more than fulfilling their mandate to give a full accounting. http://representativepress.blogspot.com/2006/09/reviews-of-without-precedent-inside.html