LUTSEN, Minn. - An Eagan man died of cardiac arrest while running a North Shore race last May, according to the Midwest Medical Examiner’s Office.

Jon Mathson, 41, was running the 25K Superior Spring Trail Race on May 20 when he collapsed on the race trail just before 11 a.m. A group of medics worked to revive him, but those efforts were unsuccessful.

The medical examiner says Mathson died of "natural cardiac arrest during exertion due to atherosclerotic coronary artery disease." He had no known medical history and was an experienced runner having completed the Superior Trail Race three previous times.

Mathson taught Earth Science and Chemistry at Eagan High School. Donations to the Jon Mathson Memorial Fund can be made on GoFundMe.