FORT CAMPBELL, Kentucky - A soldier from Panama in LeFlore County was one of two U.S. military members killed in Afghanistan Monday.

The Department of Defense says 20-year-old Spc. Robert Allan Pierce and another soldier, 2nd Lt. Justin Lee Sisson, 23, of Phoenix, Arizona, were killed when their unit was attacked by a suicide bomber.

Pierce joined the Army in April 2011, and had served in Korea before arriving at Fort Campbell, Kentucky, in August 2012.

His awards include a National Defense Service Medal, Global War on Terrorism Expeditionary Medal, Global War on Terrorism Service Medal, and an Overseas Service Ribbon.

Specialist Pierce leaves behind his wife, Christian Marie Pierce, of Huntington, Arkansas, and his parents, Randy Pierce, of Panama, and Lonnetta Dart, of Hartford, Arkansas.