Yah... well known big Al Queda target: Choctaw.
I'm sure they've been dreaming of this for years.
And how much have you heard of Beslan, until the terrorists decided to take school kids hostage?
Well the beauty of such a strike is the "Why there, and why not here?" of the matter. Plus the effectiveness of cells in the structure of a organization like Al Qaeda is that they can focus on such areas on a wider terror plan. Not saying this was terrorism, but not a suprise if so.
There's always the possibility of a "work accident". The area is semi-rural, with lot of small to large acreages. I've got some friends who live in Choctaw, and I was in the general area about 2 years ago.