A construction crew works on a building that is part of a new Ebola treatment unit built as part of Operation United Assistance in Greenville, Liberia, Dec. 4, 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)