Ten Air Mobility Command C-17 Globemaster IIIs, such as the one pictured here, and aircrews across the U.S. have been placed on alert to support relief efforts in American Samoa after a tsunami struck the region Tuesday. This alert posture allows the planes and crews to take off within hours of notification to support worldwide airlift requirements, including humanitarian relief operations. (U.S. Air Force photo/Master Sgt. Scott Wagers)