MILLSBORO, Del. (CBS) – Officials in Delaware are investigating what caused a freight train carrying stones to derail in Sussex County Sunday morning.

According to investigators, a Norfolk Southern freight train derailed at about 4 a.m. while traveling on the southbound tracks in a wooded area just north of Millsboro. They say the freight train was being pulled by two locomotives and consisted of about 70 cars.

(Credit: Delaware State Police)

(Credit: Delaware State Police)

Officials say the derailment occurred on a section of the tracks to the east of US 113.

Authorities confirm two locomotives derailed but remained upright and 15 cars were forced from the tracks, overturned and spilled their contents. All other cars remained upright.

Investigators say around ¾ of a mile in railroad track has been destroyed or damaged, however there are no hazardous conditions or threats to the environment and there are no road closures or detours.

Police and Norfolk Southern officials are investigating the incident.

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