Bret Isenhower served in the U.S. Army as a Sergeant in the 1st Battalion, 279th Infantry Regiment, 45th Infantry Brigade Combat Team, Oklahoma Army National Guard during Operation Enduring Freedom and the Afghanistan War. He was killed in action on September 9, 2011 in the Paktia province of Afghanistan when his unit came under attack by small arms fire. He had previously served in Iraq in 2007 and 2008 during Operation Iraqi Freedom.