An elderly man died Saturday while he was biking along a Lehigh County hiking trail. Ernesto Zullo, 74, of Bethlehem, suffered a heart attack while riding his bicycle on the Delaware and Lehigh National Heritage Corridor trail off Shady Hook Road and South Walnut Street in Washington Township. Special equipment was needed to bring Zullo's body off the trail. State police at Bethlehem said Zullo was pronounced dead at 2:10 p.m. by county deputy coroner Rebecca Saborsky. The coroner's office ruled Zullo died of natural causes.