Planes crash all the time. People are hardwired to look for patterns in things and sometimes we see noise that we mistake for signal. On 9/11 people saw four coincidental accidents- Boeing planes- and assumed it must be part of some bigger plot. Either it's a conspiracy we can all have fun uncovering or it's Foucault's boomerang. Neither group bothers to ask if those plane crashes are like so many others they don't do this with. The only dialectical materialism to apply is between the shitty Boeing mechanic and the plane missing components. The only conspiracy is the one you're seeing unfolding now- corporate negligence resulting in four separate tragic accidents.