Petty Officer Technician 1st Class Sean Carson, 32, of Des Moines, Wash., was killed Aug. 16 northeast of Kandahar, according to a Defense Department statement. Carson was assigned to an explosives disposal unit in San Diego.Also killed were West Coast-based Navy Special Warfare Operator 1st Class Patrick Feeks, 28, of Edgewater, Md., and Navy Special Warfare Operator Petty Officer 2nd Class David Warsen, 27, of Kentwood, Mich.The four other Americans killed were U.S. Army soldiers assigned to the Hawaii-based 25th Infantry Division: Chief Warrant Officer Brian Hornsby, 37, of Melbourne, Fla.; Chief Warrant Officer Suresh Krause, 29, of Cathedral City; Sgt. Richard Essex, 23, of Kelseyville; and Sgt. Luis Oliver Galbreath, 41, of San Juan, Puerto Rico.Three members of the Afghan National Security Forces and an Afghan civilian interpreter also were killed in the crash of the UH-60 Black Hawk, according to published reports. The cause of the crash remains under investigation.