Radnor police have identified the 65-year-old Devon man who was killed Thursday by a 45-foot-long tree limb that fell on him along the Radnor Trail.

Donald Vigliotti was sitting on a park bench in Radnor Township, Delaware County, when the 12-inch thick branch snapped at about 3 p.m., police Superintendent William A. Colarulo said. The man was pronounced dead at Bryn Mawr Hospital a short time later.

Authorities have not yet determined what caused the seemingly healthy limb to fall from its tree.

"Right now, we just believe it was an act of God," Colarulo said. "It was just a tragic accident."

The Radnor trail follows part of the bed of the former Philadelphia & Western trolley line between 69th Street and Strafford and is used by hundreds of people.

Contact staff writer Jeremy Roebuck at 267-564-5218, jroebuck@phillynews.com, or @inqmontco on Twitter. Read his blog, "MontCo Memo," at www.philly.com/montcomemo