Bryson Funk, a pitcher for the Linglestown Colts, passed away on June 12 after suffering a sudden cardiac arrest, according to a GoFundMe page organized by a relative. The cardiac arrest was reportedly brought on by myocarditis.

According to the Mayo Clinic, Myocarditis is inflammation of the heart muscle that can reduce the heart’s ability to pump blood. This can cause chest pain, shortness of breath, or irregular heartbeats. It’s usually caused by a viral infection but can also result from medication or inflammatory conditions. In severe cases, it can lead to blood clots, stroke, or heart failure. Treatment may include medication, procedures, or surgery.

Just the day before, Bryson had struck out the final batter to secure his team’s championship victory, his 9-year-old teammate Elias Vilfort told WHP-TV.

Bryson was born with a heart condition—coarctation of the aorta and a deformed bicuspid aortic valve—but family members said doctors do not believe those conditions caused his death.