From left, Willis Plummer, site manager for PAE, Steve Guiney, Zorzor Ebola Treatment Unit manager for ASPEN, and David Taylor, representative for U.S. Agency for International Development, sign paperwork, handing over the completed ETU to an international aid organization in Zorzor, Liberia, Jan. 17, 2015. 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)