A Moon Valley High School football player, who collapsed on the field and died, was not wearing a school-issued helmet, according to the Glendale Union High School District.
A district spokeswoman told ABC15 Carlos Sanchez, 16, was using a helmet that was purchased by his family for personal use.
The information was released in response to an ABC15 public records request asking about the age, quality, and maintenance of helmets worn by Moon Valley players.
Sanchez collapsed during Moon Valley's game against Cactus High School on October 20. He later died. The medical examiner said the cause of death was accidental blunt force trauma.
The Arizona Interscholastic Association, which oversees high school sports, said a review of the referees notes show no penalties were called on the final play involving Sanchez, describing it as a clean hit.
An AIA spokesman says all high school players must have NOCSAE-certified helmets, and referees ask coaches if their players are properly equipped before starting each game.
According to AIA, individual school districts can make their own rules about whether players can provide their own helmets.
Sometimes parents choose to buy personal helmets to ensure their kids have the newest, best quality helmet available.
GUHSD told ABC15 Sanchez's helmet met NOCSAE and other national standards, but the district would not release the model.
ABC15 requested additional details about whether the school maintained or inspected Sanchez's helmet, but the district did not provide those answers.