A worker was killed on a drill rig in a natural gas field in western Garfield County, Sheriff Lou Vallario said. The accident happened on a Union Drilling rig about 5 miles south of Battlement Mesa when Larry Dean Hill, 42, of Moab, fell 65 to 70 feet from the top of the rig to the derrick floor, deputy Coroner Brad Braverman said. 'He was trying to fix something and lost his balance,' Braverman said. The U.S. Occupational Health and Safety Administration are investigating.