April 17, 2013: A fire and massive explosion at a fertilizer plant in West, Texas prompted widespread evacuations.  Patients streamed into area hospitals suffering from blast injuries, orthopedic injuries and lacerations.

Crisis responders at the scene are concerned about anhydrous ammonia.
According to the Centers for Disease Control and Prevention, anhydrous ammonia is a pungent gas with suffocating fumes that is used as a fertilizer. When exposed to humans, it can cause serious problems.