The Boston bombing grabbed all the headlines but the Texas explosion is far scarier. From what I've read, there were several hundred tons of amonium nitrate that was undeclared, while you're supposed to notify if there's more than (iirc) 400 lbs. Apparently compliance is voluntary, or at least there's little by way of enforcement. Laws were flouted and many are dead. There could be dozens, maybe hundreds, of similar situations right under our noses all over the country.