A Kennecott worker was in serious condition early Friday after he was run over by a rail car Thursday night near the mining company's refinery in Magna.

Dennis Buckner, 43, was switching an empty ore-hauling rail car east of the Kennecott refinery near 2100 South when the car rolled over his right ankle, said Kennecott spokesman Greg Boyce. Buckner was taken by ambulance to Pioneer Valley Hospital and then flown to University Hospital, where he underwent surgery, a nursing supervisor said.The cause of the accident, which occurred during routine switching operations, was still under investigation Friday, Boyce said.