U.S. Air Force STAFF SGT. Dudley Lykins, from the 60th Aerospace Medicine Squadron, Travis Air Force Base, Calif., test a water botttle for ph balance, chlorine, and bacteria during Operation Unified Assistance at Utapao Air Base, Thailand, on Jan. 13, 2005. More than 18,000 U.S. military personnel are providing humanitarian assistance in Southwest Asia after a 9.0 magnitude earthquake on Dec. 26, 2004, triggered devastating tsunamis that killed over 250,000 people in the region. (USAF PHOTO by STAFF SGT. Sarayuth Pinthong) (Released)