Was that a missle?
A fertilizer plant in a small town is a great target for missiles.
Anyone saying this is a terrorist attack doesn't understand that chemical plants are dangerous. This is a factory that has tons of dangerous and explosive chemicals in it. There is a pretty decent chance of an explosion. Just look up articles, there are tons of them. If someone working there skips one of the steps their required to follow for safety there is a great chance of an accident like this.