Yup, a bit of investigation finds that this has NOTHING TO DO WITH FERTILIZER, but all of the media (with the sole exception of USA today) wen't with fertilizer in the headline.
Grain elevator explosions are extremely common; there was more than one a month during the 1990s.
Grain dust is explosive with a spark. You’d get the same effect if you were in a closed room, threw a handful of flour and lit a lighter. Boom...no more you and no more house.
Almost every small farming community in northern indiana (in fact, anywhere in the midwest) has a local grain elevator. And yes, grain dust is very explosive. Working at a grain elevator is a fairly dangerous job, because the dust is also very hazardous to breathe, and shifting piles of grain can bury an uncautious worker. This is a tragedy, but a local one. Say a prayer for the good people who make sure we have food in our supermarkets.