Two killed in crash of sheriff's office helicopter in Arizona

(Reuters) - A pilot and a mechanic died in the crash of a helicopter used by Arizona's Cochise County Sheriff's Office and a federal investigation was under way on Thursday into what caused the crash, officials said. The helicopter had just undergone routine maintenance in the Phoenix area and the pilot on Wednesday was flying with the mechanic from there to the Sierra Vista airport in Cochise County when it went down, the Sheriff's Office said in a statement released late on Wednesday. The debris field was discovered near Benson in southern Arizona, according to the Sheriff's Office. The National Transportation Safety Board is investigating. The pilot and the mechanic, who were the only two people on board the helicopter, were civilian contractors and the helicopter was leased by the Cochise County Sheriff's Office from a local company, according to the statement. The pilot and the mechanic have not been identified, pending notification of next of kin. (Reporting by Alex Dobuzinskis in Los Angeles; Editing by Barbara Goldberg in New York)