Inset: Khimberly Zavaleta (GoFundMe). Background: Reseda Charter High School in the San Fernando Valley area of Los Angeles, Calif. (Google Maps).

One 12-year-old in California is dead and another 12-year-old is under suspicion for having killed her with a metal water bottle during an altercation involving multiple students, the slain girl's family says.

Khimberly Zavaleta died in February after a violent bullying incident at Reseda Charter High School on Kittridge Street in the San Fernando Valley area of Los Angeles, according to her family.

The victim, however, was not the original focus of the bullying, police said. On the day in question, Khimberly actually stepped up to defend her older sister from being bullied by a group of students when she was struck in the head with the bottle, relatives said.

The incident is being investigated as a homicide, the LAPD said.

The attack occurred on Feb. 17. Khimberly was taken to a hospital immediately afterward and eventually sent home, according to a report by City News Service, a Southern California-based wire service.

On Feb. 19, while playing video games, she suffered what her family referred to in a GoFundMe campaign as "a catastrophic medical emergency."

An uncle later clarified the girl suffered a stroke after days of lingering headaches, according to The New York Times.

"Major blood vessels in her brain ruptured, and she was rushed to UCLA Children's Hospital, placed in an induced coma, and underwent complex emergency brain surgery," the fundraiser explains.

On Feb. 20, around 3:30 a.m., Khimberly's "heart gave out," with her family at her side, according to the online fundraiser.

Law enforcement, for its part, is largely keeping mum about the girl's death. But the LAPD has said the case is being investigated by the LAPD Robbery-Homicide Division, Valley Bureau Section.

"Due to the sensitive nature of the investigation and the involved parties being juveniles, at this time, we are not releasing any further information related to the case," the LAPD said in a statement.

The child's family has offered some details.

Over the weekend, Khimberly's mother, Elma Chuquipa, spoke with Los Angeles-based ABC West Coast flagship KABC. She described how the family understood the bullying situation at the school.

"At dismissal time, she was in the school hallway when a tall boy came up to her," she said. "He was pushing her, and my daughter told him, 'What's your problem with me? Let's go to the principal's office and talk about it,' but he ignored her."

That's when the younger girl went up to try and get her sister.

"My daughter goes and pulls her away, so they don't hit her sister, and that's when [Khimberly] gets hit in the head," Chuquipa said.

At least part of the fight was captured on video, according to KABC. The footage reportedly does not show the bottle being thrown.

"They were hitting her sister — my eldest daughter," Chuquipa continued. "In the video, you can see them pulling [Khimberly]. At one point, they hit her hard on the head, which led her to where she is now — in a morgue."

The girl's mother went on to say that her daughter was shuttled between various hospitals and the family agreed she would undergo a six-hour surgery in order to remove blood that had accumulated around Khimberly's brain.

"As a mother, I felt so bad," Chuquipa told KABC. "We got together with my family…when we got together with my family, we agreed to do the surgery, which was a 1% chance, and I said, 'There is hope.'  When we met with the doctors, they decided not to operate because my daughter's brain was already dead."

The Los Angeles Unified School District said it is cooperating with the LAPD in a statement which says officials are "deeply saddened" by Khimberly's death. That statement demurs on providing details out of "respect for the family and to protect confidentiality."

"The District remains committed to providing support to students, staff, and families affected by this loss, including counseling services and additional resources on campus," the statement goes on. "The District takes the safety and well-being of our students very seriously. We are currently cooperating with law enforcement in connection with this incident."

The charter high school includes grades 6 to 8.

On Feb. 27, a group of students at the school staged a demonstration in support of Khimberly and her family, KABC reported.

The GoFundMe is raising money for funeral services, medical expenses, time off work to grieve, and for the family to "move out of this district to a safer school for Khimberly's siblings."

"As the baby of our family, she brought a special light and joy into our lives," the fundraiser reads. "She loved her family, music, volleyball, walks with her two beloved dogs, and had many dreams for the future."