Oh, they know! They're probably just not officially admitting it. Google Anhydrous Ammonia and see if you would want to work around hundreds or thousands of pounds of it, which is how much was stored in that Plant!<quoted text>
Unlike you I don't get news from my crystal ball.
Officials still don't know what caused Texas fertilizer explosion
As I posted before, which you obviously, didn't read...it's what Timothy McVeigh used to blow up the Murray Building in OKlahoma City!