That's pretty much why I said Saudi passport holders. It was the only way they could gain internal access to the US. Nevertheless, someone, or something enabled them to qualify for the passports, to gain access, and that would have been people responsible or representative to the Saudi government.
A not so well known statistic, is that virtually everyone who was above the impact point on the North Tower, died. A similar situation in the South Tower, but due to the North Tower being on fire, a lot of people were either out of that Tower, or on their way down it, when that one got hit.