Saw a preview for this in theaters tonight - apparently doesn't release until October. Here's the trailer:
This is different from what I saw in theaters, but you get the point. Guy (Ryan Reynolds) is hostage in Iraq and apparently ends up buried alive with only lighter and cell phone. At first I thought it sounded dumb, but further research makes it seem a lot more...intense/disturbing.

I saw the preview tonight as well. Looks very interesting.