SIERRA VISTA - A 1998 Buena High School graduate was killed in action when an improvised explosive device was set off near a convoy he was riding in northern Iraq Monday. According to the Associated Press, Spc. Michael M. Merila, 23, was returning to his base camp at Tall Afar from the Mosul Airport after he and others escorted soldiers of his unit who were departing on leave. A member of the Headquarters Troop, 1st Squadron, 14th Cavalry Regiment from Fort Lewis, Wash., Merila, who was known as Matt to his friends, was the first member of the Army's Stryker...