Three years ago, Lisa Smith got a soul-crushing phone call regarding her 17-month-old daughter, Mia. The toddler was found unresponsive at her in-home day care in Pella, Iowa, after she was put down for a nap in a car seat.
According to the Des Moines Register, the daycare provider never told Smith that she regularly used a car seat for the toddler's nap time, nor that, while she took her own child to see a doctor, the provider left Mia sleeping under the supervision of an adult who wasn't certified in child care.
An investigation determined that Mia died of mechanical or positional asphyxia, which occurs when one's position prevents the child from breathing adequately. The sleeping Mia couldn't breathe while she was partially strapped into the car seat on the day care's floor.
Since her tragic loss, Smith continues to speak out about the dangers of letting children sleep in car seats outside of the vehicle. She also urges parents to check on sleeping arrangements with daycare providers.
"We want to share our story because we hope no family will ever have to experience this kind of pain and loss. Sadly, there seems to be a shocking cultural acceptance to use car seats in ways that are unsafe for children of all ages and an overwhelming lack of awareness to the dangers of placing a child unsupervised in a car seat to sleep," she wrote on Facebook.
Pediatricians warn that devices like car seats and swings that position infants on an incline are unsafe for sleeping and may allow a young child's head to roll forward, leading to suffocation and death.
"When a car seat is in the car, it's reclined at 45 degrees. This allows the baby's head and neck to rest backwards so that it's not slumped forward and blocking the airway," said Dr. Natalie Azar, an NBC News medical contributor.
If your baby falls asleep in the car, the safest thing would be to transfer them to a flat, firm sleeping surface like a mattress or crib.
Smith often sees babies kept in car seats at restaurants, on grocery store carts and along the pews in churches, but she hopes to change that.
"The hardest part is that this was so easily prevented. And we lost a daughter needlessly. No family deserves this," she told "Today."