According to New Orleans newspaper the Times-Picayune, the incident involving a 141-car Canadian National Railway train occurred just before 4pm local time near Kenner, Louisiana.
CN spokesman Patrick Waldron told the paper the train was traveling from southern Illinois to Convent, Louisiana.
It was traveling approximately five to 10 miles per hour when 14 cars left the tracks.
An investigation by railroad officials is underway, as is the clean-up of the toppled cars and coal.