A Notre Dame High School student collapsed while observing basketball practice and died Monday afternoon, school officials said.
After her collapse, Nikki Valdez, a freshman basketball player, was taken to an area hospital, where she died, said school President Brett Lowart. It is unclear what led to her collapse, he said.
"The Notre Dame community will assuredly come together in faith, as it always does, to comfort and support the Valdez family and one another," Lowart said in a statement.
School officials said they were formally announcing the death Tuesday morning, allowing any student who knew Nikki and her brother, Addison, a junior at Notre Dame, to meet in the campus gymnasium for grief counseling.
A prayer service has been set for later in the day, they said.
Nikki is second Notre Dame high school student to die in the last four months.
In August, senior Chris Kelly was killed in a fiery car crash in the 17000 block of Rinaldi Street in Granada Hills.