"She was taken from us so young. She didn't even make it to her 16th birthday," Kevin Guerrero said about his niece Ariahh Slemaker.
The crash happened shortly after 4 a.m. Monday. Dashcam video shows a Hyundai Sonata speeding and then crash into attenuators, causing the car to flip and burst into flames.
Ariahh was with her best friend George Dobbs, also 15 years old. The teenagers and three other people in the car died. A sixth passenger suffered critical injuries.
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Angel Sixtos, 18, was identified Tuesday as the third victim killed in the solo-car crash.
Guerrero said everyone in the family is devastated over what happened.
"It was a surprise and a shock to us all... This family has never felt this much trauma," Guerrero said. "And yet we are still staying strong, trying to keep it together. And it could happen to anyone. You wish it upon no one."
Guerrero says he doesn't know the connection between the teens and the others in the car.
Ariahh's family has set up a GoFundMe account to help with funeral costs. The family of George Dobbs has also set up a GoFundMe account to help pay for his funeral. The two were best friends, like brother and sister, according to family.
Why the teens were out at 4 a.m. is something the family is still coping with.
"It's not natural for parent to have to bury their kid. No one should ever have to go through that pain," Guerrero said. "Especially when you go to bed knowing your child is asleep in the bedroom, and you wake up and she's gone.
"Mistakes happen. No matter how much you try to prepare your kids for it. Mistakes happen and we gotta live with it."