Angela Gettis, a 16-year-old sophomore at George Washington Preparatory High School in South Los Angeles, collapsed on the field at Fremont High School about 9:10 p.m. She was taken to the hospital, where she was pronounced dead about three hours later.
Los Angeles Unified School District officials said it was apparently the result of sudden cardiac arrest. The girl's family said she had no known medical problems.
"Washington High School, like every other high school, has its share of unfortunate incidents regarding youth," Washington Prep Principal Todd Ullah said. "We prepare for that, but you can never really prepare for that. It's devastating. It's tragic."
Ullah said Gettis was a good student and a leader on campus. She was a member of the Junior Reserved Officers Training Corps and had planned on going to college and majoring in forensic science.
"I just want people to remember the heart she had. She was very kind," said Angela Kirkindoff, Gettis' aunt.
Crisis counselors will be at the school Monday to help students and faculty deal with her death.
