end of the recording. so it really is a very chilling read of these final moments of that germanwings flight that went down in the alps dana. absolutely terrifying. fredrik, thank you for that report. appreciate it. here with us now, charlie pereira, former ntsb investigator who co-wrote the first chapter of the 9/11 commission report. thank you for joining me. first your reaction to what we know detail by detail of the last final minutes? well for the families it s another horrible piece of data that indicates what their families went through. that s the worst part of all of this. yes. for investigators, these are what we call establishes boundary conditions for the reconstruction of the flight after the airplane. there will likely be ground scars or witness marks where the wing reportedly hit the mountain. we typically go out to those areas and search along the flight path for trees that have