Was the crash of two planes into WTC a total surprise? I suggest we believe not so and on the long run it proved to be absolute nonsense. The intelligence community was well informed and should have mathed with airplanes as weapons. There has been a kind of strange silence - or say behaviour - about terrorist activities and al Quaida before 9-11. Please note this article:
What the U.S. Knew: 9-11 Bombshells
What the U.S. Knew: 9-11 Bombshells