The early reporting was an accident, as you well know. Then the second plane hit with all eyes on it.
I found it quite enlightening the morning of Sept 11. As I remember it, Matt Lauer (and everyone) was watching the first tower burn, talking about the accident, and wondering how the pilot could have been so confused, and raising very slightly the possibility that the pilot may have been suicidal, and all of a sudden the second plane hit the second tower. Took half a second for Matt to say: "The nation is under terrosit atatck."
They know. But they hide what they know. Until it cannot be hidden nay longer.