DES MOINES, Iowa (AP) — Gov. Terry Branstad has ordered flags flown at half-staff to honor a Marine with Iowa roots who was killed in a helicopter crash in Afghanistan. Master Sgt. Travis Riddick died on Jan. 21. A memorial service is scheduled for Sunday at Centerville High School. Branstad has ordered all U.S. and state flags flown at all state buildings to be flown at half-staff beginning at 5 p.m. today (Friday) until 8 a.m. Monday in honor of the 40-year-old Riddick, who is formerly from Centerville. Branstad also encourages individuals, businesses, schools and city and county offices across Iowa to lower their flags to half-staff during those hours as a sign of respect.