A Dubuque, Iowa, man was pronounced dead at the scene of a single-vehicle accident Sunday afternoon about 1 mile northwest of Sabula, Ill., according to the Jackson County Sheriff’s Office.

Daniel Allen Frey, 60, was pronounced dead after the accident that happened shortly before 3:45 p.m. on 607th Avenue (Evergreen Avenue), said Deputy Russ Long. Frey was the driver and only occupant of a 2011 Ford utility van registered to his employer, Rich & Junnies Coin Inc., of Dubuque.

Frey was driving south on 607th Avenue when he drove off the right side of the road no apparent reason, Long said. He continued 228 feet along the roadside and ditch, then struck a tree.

Long said a medical condition might have contributed to the accident and to Frey’s death.

The Jackson County medical examiner and the Jackson County Sheriff’s Department continue to investigate the accident. Sabula ambulance and fire crews assisted at the scene.