norfolk southern train was traveling near trenton , south carolina , friday .
it was transporting anhydrous ammonia - highly toxic , dangerous chemical .
it derailed shortly after 8.30 pm after apparently hitting a tree on the tracks .
up to 15 cars overturned and leaked ; haz mat crew was dispatched to site .
incident sparked evacuation of 30 people with 1.5-mile radius of the scene .
authorities confirmed friday night that no one was injured following crash .