LOWER BURRELL — A Pennsylvania high school football player who died after collapsing during the year’s first practice had a heart tumor, authorities said Thursday.

Noah Cornuet, 16, died of natural causes after an autopsy revealed the noncancerous growth, the Allegheny County medical examiner’s office ruled.

Cornuet was a sophomore at Burrell High School in Lower Burrell, about 25 miles northeast of Pittsburgh. He had reportedly just finished sprinting when he collapsed while walking off the field Wednesday evening.

Paramedics who attended the practice as a precaution immediately went to help the boy, who died at Alle-Kiski Medical Center about an hour later.

The Pennsylvania Interscholastic Athletic Association began requiring schools last year to hold three days of practice to get players used to the heat before they’re allowed to have contact drills.

The PIAA instituted the rule because of an increase in heat-related player deaths nationwide in recent years. The high temperature Wednesday was about 80 degrees.

“The Burrell School District community recognizes the tragic loss of a student tonight,” Superintendent Shannon Wagner said in a statement Wednesday.

A crisis team is available to help students and staff cope with the loss, the statement said.

Under the new PIAA rule, players were allowed to wear helmets and shoulder pads Wednesday and Thursday, and full gear on Friday. But there was to be no contact at those practices. Regular, full-contact practices were to begin Monday.