NEW HOLLAND (AP) — Authorities say a 76-year-old farmer has died after he somehow got pinned under a tractor harrow at his Pennsylvania farm.

New Holland police responded to Roy Mentzer’s farm around 7 p.m. Thursday. He was pronounced dead in a field there a short time later.

Authorities say Mentzer was apparently pinned under the harrow while attempting to perform maintenance on it. But he was alone at the time, so it’s not clear how that occurred.

The death is being investigated as an accident.

Mentzer’s death was the third farm-related fatality in Lancaster County this month,