"There's nothing about the car seat that's designed to sleep. Of course, if the straps aren't tight, the child can kind of slump down," Sharon Evans, a trauma injury prevention coordinator at Cook Children's Hospital, told WFAA.
The straps can also strangle a baby or their heads can flop down, preventing them from being able to breathe.
A study published in the Journal of Pediatrics found that 31 children died while sleeping in car seats over the four-year study period. The study also found that 16 other children died while sleeping in other devices like a stroller or bouncer.
Mia’s mother, Lisa Smith, warns parents and caregivers by sharing her family’s story as often as she can.
"I walk around town and see people using a car seat on the seats at restaurants or putting them on the floor at tables," Lisa Smith told WFAA. "I literally walk up to people and I say, 'You know, I had a daughter who was 17-and-a-half months who passed away and I just want you to be really careful.'"
“She was our first born, our only child, and she didn’t deserve what happened to her,” she said. “But other families don’t deserve this to happen to them either.”