The First Step in Any Historical Narrative
The first step is an hour-by-hour timeline, followed by a minute-by-minute extension if the documentation allows it.
If you don't know the sequence of events, you are not in a position to discuss the causes of these events.
This is what I produced for my 1,000-page history of the Northern Presbyterian Church, 1706-1936: Timeline.
This is clearly what is needed for any assassination theory.
In the case of the 9/11 attacks on the twin towers, there is minute-by-minute documentation. Anyone who comes to you with a theory of 9/11 had better offer a website that shows the sequence of events. This website should link to publicly verifiable documentation of the exact time of the event in question. Until there is a minute-by-minute timeline of events, the theory underlying the sequence of 9/11 is more theory than fact.
A website should be available on this issue. There should always be discussion forums, perhaps behind a subscription wall, where people can debate the documentation of a particular event. There will be debates over what constitutes valid documentation. The site should be updated by a general editor on a regular basis. If somebody on the forums discovers a discrepancy in either the time or the documentation, the editor of this site should make a decision about which time or document should be the foundation of the timeline. He should be honest enough to refer people to a debate over the time or the documentation if the debate exists. He has to come to some conclusion, but he should make it clear to readers the reasons why he chose one time and one piece of documentation over rival choices.
It doesn't matter whether the timeline supports a conspiracy theory or an establishment theory. The timeline should be open to anyone for comment.
Grand theories are a dime a dozen. Accurate timelines are the equivalent of the gold coin standard. They don't exist. Yet a timeline should always be the basis of any historical narrative.
People are lazy. They may go to work to promote a favorite theory behind some famous event, but only the motivation of producing an article, book, or website that is exciting to read gets people to devote this kind of effort. A timeline is not exciting to read.
The grunt work of establishing a verifiable timeline is laborious, and it requires painstaking attention to detail. There is almost no payoff for such work. Nobody will pat you on the back to tell you what a great job you have done.
Until you see a timeline of events to support any historical narrative of what is said to be a turning point event in history, you can be sure that a lot of work still needs to be done.
The great British historian A. J. P. Taylor argued that World War I broke out primarily because of military railroad time schedules. Generals had to make decisions soon enough for them to get the troops and materials to the front lines. I think his theory of why World War I broke out when it did is the best available theory. It gets right to the nitty-gritty: the timing of the sequence of events, both in military theory and fact.