OK, so I was re-reading things, and was surprised to remember I'd written that this trailer had also brought tears to my eyes (like a certain Irish Sara's latest fic) . . . I forget things too easily.
I'm also really lazy, 'cause then I went into this description on IRC of why the trailer was so powerful . . . and realized I wasn't about to bother to add it to the more permanent thread. So I decided I was going to anyway, in an attempt to change my lazy streak.
So here's why it brought tears to my eyes:
The music was all creepy for half the trailer; you could feel the tension and the awfulness.
And then it turned to sad; you could *feel* the damage that had been done, and the clips you chose only added to it.
And seconding the "Very well done!" One of my favorite trailers of all time.