The body count would've probably been higher than 19. The passengers on those planes where dead when they took off, but hopefully the would've crashed someplace isolated like near Pittsburgh.
Now, I don't want to go off on a rant here, but those people who laid down their lives to prevent the fourth attack trancend a word so paltry as "hero." We will never know how many lives they saved by stopping the BGs, and dieing out of harms way.
Make no mistake, these terrorists are the proverbial bad guys in the way that small children in '79 had no illusions of Darth Vader's good/evil status as he strode through the smoking hole in the hull of the "Blockade Runner". That was the fear they felt, and unholy horror they faced without so much as a light scalpel.
I hope I never have to face anything like that, and fear I would fare well against the Lovecraftian realization that I was dead the moment the landing gear left the tarmac. I was nearly reduced to a white haired drooling wretch with my sleeves buckled in back just from the relative safety afforded by the associated press. The truely terrorizing thing is that none of us saw it comming. If nothing else, it proves the power of knives if they can take out a double skyscraper, and the symbolic edifice of the indominable American war machine.
