Just from the trailer, lets see if I can guess the plot of this movie.. cause I've seen this before...
A normal unsuspecting town gets some military experiment preformed on it which causes it's inhabinents to go crazy in a zombie-like state and start killing each other.
Then when things get too out of control, the military step in and start killing everybody to "cover-up" their mess, with the climax being that the entire town getting nuked off the face of the map.