MILLERSVILLE (AP) – A riding lawnmower being used by a groundskeeper at Millersville University caught fire, killing the groundskeeper. University President John Anderson says in an email to faculty and students the worker, 60-year-old Michael Keefer, died Wednesday. He says Keefer was riding on the lawnmower near the university’s stadium when the fire broke out. Keefer was taken to a hospital and died that night. The Lehigh County Coroner’s Office said cause of Keefer’s death was thermal injuries and the death was an accident. A university spokeswoman says it’s unclear what caused the fire. The university and the state fire marshal are investigating. Keefer had worked at the university since 1990.