Two 15-year-olds are in custody after McLoud police say they shot and killed a 16-year-old girl.
Officers said a group of teenagers were at a house on Friday.
Investigators aren't releasing many details but said 16-year-old Kaylen Thomas died from a gunshot to the head.
Police arrested a 15-year-old boy and girl on Sunday for manslaughter.
Kaylen's mother said she can't imagine why anyone would do this to her daughter.
"She was so happy. She loved school. And everything about it. She was involved in everything. She was just finishing up cross country," said Cynthia Thomas.
Kaylen's friends asked classmates to wear her favorite colors, blue and purple, to McLoud High School Monday.
A GoFundMe page has been set up to help Kaylen's family.