A La Pine man driving east on Highway 58 died in a single-vehicle crash Thursday.

Robert Bieler, 81, was driving a GMC St. Vincent De Paul delivery truck near milepost 32 when, for unknown reasons, he failed to negotiate a curve, left the road, traveled down an embankment and hit a large oak tree, according to the Oregon State Police. The accident happened at about noon, and Bieler was pronounced dead at the scene.