According to the Chino Valley Unified School District, the student suffered some sort of medical emergency at the school's aquatic center on Friday.
At the time, officials didn't release details regarding the incident, saying only that the student was "in distress."
The student wasn't identified, but the school district described him as "an outstanding student, compassionate friend, and fierce athlete."
"The entire Chino High School community and Chino Valley Unified School District would like to offer our sincerest condolences to our young Cowboy's family and friends as they process and cope with the tragic loss of their loved one," read a statement from the district. "We are asking for our community's continued support as our student's parents and sibling prepare to adjust to life without their beloved son and brother. This is a very sensitive transition, and the family has requested that we respect their privacy as they heal together. We would like to encourage everyone to afford the family this act of kindness and to respect their right to discretion."
Counseling services have been made available to students in need of assistance.
The incident remains under investigation.