WASHINGTON (AP) — The Army has named a new commander at Fort Riley, Kansas, to replace an officer who was fired Monday, just weeks before soldiers from the 1st Infantry Division deploy to Iraq. Major General Joseph Martin is assuming command of the division. Martin replaces Major General Wayne Grigsby, who is the subject of an Army investigation and was removed from command. The Army hasn't released details of the investigation. Martin is a 1986 graduate of the U.S. Military Academy at West Point, and recently was commander at the National Training Center in Fort Irwin, California. He deployed to Iraq twice as a commander during the Iraq war. Brigadier General Jeffery D. Broadwater will take command of the National Training Center. He's currently deployed to Afghanistan.