TARNAK, Afghanistan (April 9, 2010) Seabees from Naval Mobile Construction Battalion (NMCB) 133, Detachment Six use an excavator and shovels to fill Hesco barriers with sand during the construction of a security wall in Tarnak, Afghanistan. NMCB-133 is in the U.S. Central Command area of responsibility. (U.S. Navy photo by Chief Mass Communication Specialist Ryan C.Delcore/Released) 100409-N-8816D-156