PITTSBURG COUNTY, Oklahoma - A Union Pacific train derailed in Pittsburg County Sunday morning. 

Union Pacific said the derailment happened north of Kiowa, Oklahoma just after 6:30 a.m. They said 16 rail cars and the rear-facing locomotive derailed. 

No injuries have been reported and no hazardous materials were involved in the wreck. 

The cause of the derailment is still under investigation.