Not necessarily true... How much resistance would you expect failed floors to exert on the rest of the falling structure? The facade of the building could have fallen appreciably faster than the internal support columns and were that the case we wouldn't be able to confirm that theory from the available video takes of the collapse. After all, we can only see what occured to outside of the building. The flip side is that the support columns could have crumbled before the s of the building followed suit. Again, no existing video clips of the collapse can confirm or debunk either theory because internal footage of the collapse, the 'smoking gun' element in this argument, does not exist...