I know this is all over the place by now, but just in case you haven't seen it, there is a photo essay on 9/11 using digital photos taken by a guy who was killed when the 2nd tower came down.
I like the story. It is a good story. It is not a sad story. What I like most of all is that the word "hero" is not mentioned once. That is what makes it real. To have called him a hero would have been wrong and detracted from the amazing pictures. He was photographing heroes. He wasn't helping. I would like to know the rationale he had for not helping these people. I would think that being a human being would outweigh being a journalist in a situation like this, but, obviously I am wrong.
To paraphrase Bobcat, "If you ever see me getting covered by a falling building, put down the camera and come help me!"
I have found it helpful to do the stretching exercises my physical therapist recommends. Do some core strengthening exercises, such as the ones highlighted at The Mayo Clinic. By keeping your core strong, your back won't put itself in a position to cause that sciatica pain you are having.