Restaurant patron fells one armed robber and scares off another, KDFW, Dallas, Texas 03/17/16, KXAS, Dallas, Texas 03/17/16

A pair of armed men went up to a diner at a Whataburger restaurant in Dallas, Texas and attempted to rob him. The diner turned out to be an off-duty security guard that was armed at the time. The armed customer drew a gun and fired at the robbers, striking and killing one. The customer was not harmed during the incident.