A 12-year-old girl in Missouri fatally shot her teen cousin and herself while they were playing with guns during a live stream video at a birthday party, police said.

The young girl, identified Paris Harvey, 12, accidentally shot her cousin Kuaron Harvey, 14, while they were live on Instagram around 2 a.m. Friday. The gun Paris was playing with went off and killed Kuaron while they were making the video in front of a bathroom mirror, prompting Paris to then shoot herself, police said, ABC News reported.

When the officers responded to the scene, the children were found unconscious and not breathing at an apartment in St. Louis. They were both pronounced dead at the scene.

Although the police initially described the incident as a murder-suicide, the family said it was a "tragic accident" that happened while the duo was playing with the gun at the apartment they had rented to celebrate birthdays in March.

"It was no murder. It wasn’t a suicide. It was a freak accident. It happened," Paris’ heartbroken mother, Shinise Harvey, told the St. Louis Post-Dispatch.

Kuaron's mother and Paris' father are siblings. Both the children were raised close to each other like siblings. They often made videos together and loved pulling pranks on each other, the family said.

"It wasn’t a situation where they were arguing or anything like that. They were playing with the gun when they shouldn’t have been. Of course, they shouldn’t have been doing it. I think it just went off. It went off by mistake," Paris’ grandmother, Susan Dyson, from Dallas who witnessed the incident on Instagram said.

The family believes that the gun went off when the duo was "trying to be too hip." After Kuaron was shot, Paris reaches for the gun, but it goes off again, they said.

The family fondly remembers Paris as a funny seventh-grader who loved getting her hair and nails done, while Kuaron was a goofy eighth-grader who loved doing backflips.