MATTHEW BROWNBILLINGS, Mont. (AP) â¿¿ A central Montana precious metals mine was under a partial closure order Tuesday as authorities investigated the death of a worker who crashed while driving a piece of equipment 1,200 feet underground. The victim was identified by Stillwater Mining Company as Dale Alan Madson, 42, a lead equipment operator who lived in Bearcreek and had worked at the mine since 2008. Amy Louviere with the Mine Safety and Health Administration said Madson was killed Monday afternoon as he was driving a piece of mine equipment with an enclosed cab that went into a ditch. A rock bolt struck Madson in the neck, she said. It was the mine's first worker death in more than six years. Stillwater Mining Co. spokesman John Beaudry described the accident as isolated and said further details would come out following a federal investigation. "We are all grieving. Our thoughts and prayers are with friends and co-workers," Beaudry said. Stillwater Mining is the country's only producer of platinum and palladium, which are used for jewelry, in catalytic converters for cars and in various industrial applications. The mine near Nye employs about 900 people. Underground work at the mine was suspended Tuesday as the accident was under review by the company and investigators. Work was to resume Tuesday night, although the area of the mine where the accident occurred was to remain closed. Louviere said there was no end-date on the federal closure order. Federal safety records show that Stillwater had 74 significant safety violations during the prior 12 months ending on Sept. 30. Its rate of violations during that period was below average for the underground mining industry. Madson lived in Bearcreek with his wife, Melodie Betts, and had two teenage daughters in Missoula from a prior marriage, said his grandfather and namesake, Dale Madson, of Vancouver Wash.