PHILADELPHIA (AP) — Authorities say the death of a north Philadelphia prep school football player who collapsed during a workout was due to natural causes stemming from a cardiac condition.

The Philadelphia medical examiner’s office said Wednesday that 15-year-old Ryan Gillyard of Upper Darby died of hypertrophic cardiomyopathy, a condition that causes thickening of the heart muscle.

St. Joseph’s Prep officials said the freshman collapsed shortly after warm-ups April 18 at the school’s practice field. He was rushed to Temple University Hospital, where he was pronounced dead.

Officials said Gillyard played for the team as a linebacker and running back and also played basketball at St. Denis Catholic school in Havertown.

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