A 19-year-old Poulsbo man who collapsed after skimboarding at Point No Point county park in July died of natural causes.

Gunnar Strum likely died of cardiac arrhythmia, or an irregular heartbeat, according to the Kitsap County Coroner’s Office.

His heart was found to be enlarged — cardiomegaly — with some mild scarring.

The young man, who lost his younger brother to cancer in when Strum was 9 years old, may have had the defect in his heart his whole life, the office reported.

Strum was a member of New Life Church and planned to transfer to Seattle Pacific University.