Taiwanese authorities say a BK-117 medical helicopter has crashed off the island's west coast killing one person and leaving another missing. The Civil Aeronautics Administration says the helicopter with three people on board took off from Taipei to the outer island of Kinmen at 2:54 a.m. Friday (1854 GMT Thursday) and lost contact about 4:20 a.m. (2020 GMT Thursday). It says the pilot survived but the co-pilot died after medical treatment. A passenger identified as a medical professional is missing. Kinmen is 172 miles (277 kilometers) west of mainland Taiwan just off the Chinese coast.