My understanding of fertilizer explosives is that the stuff destined for Home Depot won’t do the job. You need at least 32% Ammonium Nitrate and that’s not sold over the counter at a box store. Maybe someone else knows a little better, but I doubt there’s any potential here for terrorism.
Maybe they’ve learned how to extract the ammonium nitrate
from the mix, might take a few chemical steps, then viola.
Here’s a thought. What percentage of Amonium nitrate does this type of fertilizer have? Any at all? If it does it may be possible to take enough out of 10,000 pounds to make a fair sized bomb. I would think you could leach it out of the fertilizer if it contained any.