By Nia Williams (Reuters) -Six people were killed after a small plane carrying global miner Rio Tinto’s workers crashed near Fort Smith in Canada’s remote Northwest Territories (NWT) on Tuesday, the NWT Coroner Service said on Wednesday. Four passengers and two North Western Air Lease crew members died in the crash, Chief Coroner Garth Eggenberger said in a statement. There was one survivor who was treated at the Fort Smith Health Centre before being taken to hospital in the provincial capital Yellowknife. The plane had been travelling from Fort Smith to Rio Tinto’s Diavik Diamond Mine, locate…