Health officials issued an urgent warning after a train carrying toxic materials derailed and exploded into a fireball in North Dakota. Hazmat crews have been deployed to a remote area around 140 miles north of Fargo, after 29 cars of a CPKC train derailed at around 3:45 am on Friday. The hazardous materials in the train included anhydrous ammonia, sulfur and methanol, which officials warned are being expelled from the wreckage in toxic smoke. Ammonia is the biggest risk, and if exposed to the compound, it can cause burning to the eyes, nose and throat, as well as blindness, lung...