Explosion at Nebraska railyard prompts evacuations because of heavy toxic smoke

An explosion inside a shipping container at the world's largest railyard prompted evacuations in western Nebraska Thursday because of the toxic smoke generated when one of the chemicals aboard caught fire. The explosion occurred around noon inside an intermodal shipping container on a railcar at Union Pacific's Bailey Yard in North Platte, though it wasn't immediately clear what caused the explosion. Railroad spokeswoman Robynn Tysver said no one was hurt. Authorities evacuated everyone within a four-mile radius of the railyard, which is about 280 miles west of Omaha. Tysver said one of the containers involved in the fire was carrying perchloric acid which is used in explosives and other products.