Try talking to people who saw it in person. From what I understand, quite a few happy-go-lucky folks are now grim people in counselling because of it. Early on, the NYC news showed a man hanging outside of his window, waving his jacket for help and then they cut it, implying that he jumped/fell. From the numbers I've heard, hundreds must have jumped or fallen. The phrase that sticks with me the most, used by a person who fled the towers, was "piles of blood". Blood normally doesn't sit in piles.
I remember that video of the person on a top floor waving a jacket, signaling for help.
It's possible that not everyone on the floors that the planes hit was immediately killed. There were internal partitions on the floors, right? So, someone on a farside of the building from where the plane impacted might not have been engulfed in the fireball, but would have had to face advancing flames and smoke.
The fire also worked its way upward. So, the choice the trapped people had was the worst possible one: Stay and die from the fire and smoke, or jump and die from the fall.
We do need to see the graphic pictures, and not let this be a "sanitized" event like so much of history has been "sanitized for our protection." Not that we need to be ghoulish about it, either, but much of the true horror of that day has been smoothed over. And sadly, much of the raw video that went out live is now gone or no longer available.
I should have fired up my VCR when this happened, but didn't think to do that until hours later. Like many, I sat before the TV, transfixed in horror at what I did see.