TUCSON - How secure are U.S. military installations? You would think the answer is: very. But, as the News 4 Tucson Investigators uncovered, one installation, right here in southern Arizona, continues to face potential outside security risks, and the problem doesn't seem to be getting any better. Fort Huachuca is only 15 miles north of our state's border with Mexico. The Army post covers more than 73,000 acres. In many parts, the terrain is steep and rugged. Much of the work that goes on at Fort Huachuca is classified but, as the News 4 Tucson Investigators learned, keeping people who...