FORT RILEY, Kan. (AP) — A brigade of the Army's 1st Infantry Division is preparing to leave Fort Riley for a yearlong deployment to Afghanistan. The 4th Infantry Brigade Combat Team will hold a ceremonial casing of its colors Thursday at Cavalry Parade Field on the northeast Kansas post. The flag will be unfurled again when the unit arrives in Afghanistan. It's the brigade's third deployment since 2006 and its first to Afghanistan. The soldiers will work with Afghan government and security forces to help stabilize the country.