First Lt. Nathaniel Zimmerly, a contract officer for Joint Forces Command – United Assistance, tours an Ebola treatment unit built in support of Operation United Assistance prior to handing over the facility to a international aid organization in Tappita, Liberia, Dec. 27, 2014. United Assistance is a Department of Defense operation to provide command and control, logistics, training and engineering support to U.S. Agency for International Development-led efforts to contain the Ebola virus outbreak in West African nations. (U.S. Army Photo by Sgt. 1st Class Brien Vorhees, 55th Signal Company (Combat Camera) / Released)