TexasCHLforum.com

It was ruled electrical malfunction:

Investigators have ruled out foul play, and that includes any accidental explosion involving ammunition inside the structure. They believe an electrical malfunction sparked the flames in the gun range on Highway 377 southwest of Benbrook.

http://www.wfaa.com/news/reports-fire-t ... e/27684585

I saw the owner on one of the local news stations tonight. He said he is going to rebuild but it will take time. At the time of the fire there were almost 40 people in the building when it started. ATF is investigating but the news reporter said it did appear to be an electrical malfunction. His retail building was apparently not damaged.