Peshawar, Pakistan (CNN) -- It was the computer classroom where I cracked. I'd managed to remain detached until then. I wanted to tell the story. Look, but don't internalize, was the mantra I was repeating inside my head.

Tell the facts, explain what you are seeing and what happened. I focused. I don't think I've been somewhere with so much blood on the floor.

Over the years, covering wars, I've seen more than my share. Sarajevo, the war in Bosnia as Yugoslavia tore itself apart, was an inoculation against my visceral fear of the red stuff.

In that conflict, mortars ripped through crowds of civilians. I soon learned how head wounds bleed. It's different. You don't forget.

Here it was again in the auditorium. Dark and heavy. Don't think, focus and do your job, I was reminding myself.

But after a while I couldn't. These were children, innocents. Parents not far from here are suffering a harrowing pain none of us can imagine. Parents, whose job in the army is to protect their country, not able to save their own children.

The army officer showed us the doors where the children had tried to break out of the auditorium to run away from the Taliban gunmen.

The carpet is sticky and red. The floor tiles a mess of the worst of Sarajevo. The Taliban could not have been more callous and calculating. Where the children were most concentrated they turned their automatic weapons on them at point-blank range.

Cold-blooded murder. The officer tells me close to 100 children were gunned down right here.

Again, I'm telling myself to focus. Explain this brutal cowardly act.

Leaving the dark, sad auditorium for the light of day I feel I can breathe better. I look up at the sky. It's the color of hope -- clear blue and not a cloud to be seen.

I shouldn't have looked down again. I'm walking over to the classrooms at Army Public School and Degree College. Drops, smudges, pools of blood are everywhere. I'm becoming conscious that I'm trying not to step on them.

It seems disrespectful somehow.

How, I am thinking, could the Taliban be looking for even more bloodletting when they have already killed so many? But they are.

That's when I get to the computer classroom, maybe 30 feet long by 15 feet across. Computers on rough benches down each side of the room. Space for maybe a dozen or so children to hone their computer skills.

You didn't have to be rich to send your child to this school, and in Pakistan -- in Peshawar in particular -- on a global scale that implies your means might be quite humble indeed.

Quite possibly some of these kids wouldn't have a computer at home. In our ever-interconnected world, lessons in this room could have been some of the most valuable to their futures.

And that's it. I'm standing there realizing they have no futures now.

The base horror that took place here is startlingly and immediately evident. Chairs still at computers, thick blood pooled underneath on the tile floor.

The gunmen came in and before the children could escape opened fire.

As I try to explain all this on camera, I can feel my voice cracking. It's not a conscious thing, its what the brain does, a self-defense maybe. Such a horrible waste of so many bright futures, so many parents in pain.

It hurts, and there is no getting away from it.