The tragedy unraveled on a gravel driveway at a home in Tennessee, where a family’s dark blue pickup truck sat, eerily, with a rear door still ajar and an empty car seat lying beside it on the ground.

Authorities said it was there, in East Nashville, that a father said he forgot his 1-year-old daughter in a hot car Wednesday and, sometime later that evening, the mother discovered the child.

The Metropolitan Nashville Police Department said on Twitter that the child was taken to Vanderbilt University Medical Center, where she was pronounced dead.

The incident marks at least the seventh instance in which a child has died in a hot car this year, according to data from, which has been tracking child vehicular heat-stroke deaths since 1998. Over the past two decades, an estimated 37 children have died of heat stroke each year in the United States, according to the website.

It was about 7:30 a.m. Wednesday when Matt Barker took his 1-year-old daughter, Katera, and her 5-year-old sibling to day care, Nashville police said in a statement to The Washington Post.

Barker reportedly dropped the older child at a day-care center in Nashville but forgot Katera, who was in her car seat in the back of his truck, police said. Then he returned home, police said, parked the vehicle in the driveway and called a ride-share service to take him to the airport, where he planned to catch a flight for an out-of-town business trip.

The children’s mother, Jenny, went to work in her car, police said.

It wasn’t until that evening when Jenny Barker went to pick up the children from day care that she learned that her younger child had not been dropped off, police said.

“She telephoned her husband and came to the realization that Katera was still in the pickup truck,” police said in the statement. Police said that as she pulled into the driveway at the home on Virginia Avenue, she dialed 911.

“She removed Katera from the pickup truck and began CPR until paramedics arrived,” police said.

Police said the toddler was pronounced dead upon arrival at Vanderbilt University Medical Center.

Temperatures in Nashville averaged about 70 degrees Wednesday, but experts say that inside a vehicle, it can get much hotter.

In a study released Thursday by Arizona State University and the University of California at San Diego School of Medicine, researchers compared temperatures inside six vehicles in Tempe, Ariz., where the heat climbed into the 100s. They found that vehicles parked in the shade hit nearly 100 degrees within just an hour. When vehicles were parked in the sun, the temperatures rose to 116 degrees.

“These tests replicated what might happen during a shopping trip,” Nancy Selover, a climatologist and research professor at the School of Geographical Sciences and Urban Planning at Arizona State, said in a statement. “We wanted to know what the interior of each vehicle would be like after one hour, about the amount of time it would take to get groceries.”

But, the researcher said, what surprised them was the surface temperatures.

When vehicles were parked in direct sunlight, the seats averaged 123 degrees within that same period. Steering wheels, 127 degrees. Dashboards, 157 degrees.

“We’ve all gone back to our cars on hot days and have been barely able to touch the steering wheel,” Selover said. “But imagine what that would be like to a child trapped in a car seat. And once you introduce a person into these hot cars, they are exhaling humidity into the air. When there is more humidity in the air, a person can’t cool down by sweating because sweat won’t evaporate as quickly.”

The situation can turn dire when a body temperature reaches more than 104 degrees and a person cannot cool down. In such cases, the person can experience heat stroke — becoming dizzy, disoriented and confused, feeling fatigued or falling into a coma, according to the National Institutes of Health. When the condition is not properly and promptly treated, it can lead to death.

In the recent study, the researchers discovered that a young child trapped in a hot car in the sun could reach life-threatening temperatures in about an hour.

Following the hot-car death in Tennessee, NewsChannel 5 reported that the child was recently adopted by the Barkers and celebrated her 1st birthday with them.

Her birth mother, who was not publicly identified by NewsChannel 5, told the station that she learned about the toddler’s death Wednesday night when the adoption agency informed her that there had been a terrible accident. She said she was devastated by the news and she wants to know what exactly happened.

Police said the father flew home Wednesday night and that the couple have been cooperating with the police investigation. No charges have been filed, police said.

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