I'm still watching it (recorded it) and I'm sat here with tears in my eyes. I've seen so much footage of this over the years, but all these "private" camcorder images just amplify so much and make it so much more real. I am honestly shocked, and so moved...

I can't help but think some of the faces of the firefighters seen earlier in the program, as they assemble outside the buildings just after the planes hit - they died in the collapse. Some of the voices on tape - those people died that day.

I brings home just how real and terrifying this event was. But also just how awesome it was. I don't mean "awesome!" in a good way, I mean on a magnitude level. How one of the most famous skylines was changed in less than ten seconds, and as the program title says, how America, but also the world, was changed completely in 102 minutes.

Truly TRULY tragic

The scenes of firefighters calling their families and wives to tell them they are ok. The guy that was 15mins late for work and survived because of it.

Chilling

R.I.P. to all those poor souls and brave men and women that lost their lives.