Children’s laughter fills the halls of Dee Dee Estis’ two-bedroom apartment. Toys are scattered throughout the house and child-safety measures in place to ensure no one gets hurt. In a back bedroom, Estis’ 6-year-old daughter, Bailey, plays with a friend.

Hanging on the walls are pictures of her 3-year-old son, Christian LaCombe, a brown-haired, blue-eyed boy his mother describes as an adventurous goofball with a contagious smile who can make the grumpiest person in the room grin; a caring, compassionate boy, who’s willing to do anything for those he loves.

He’s a boy who loves hiding behind the couch, waiting for Estis to walk by so he can attack and pounce on her back. He loves the movie “Cars” so much, Estis estimates he’s watched it at least a million and a half times. And he has a knack for memorizing song lyrics, especially “Life Is A Highway” by Rascal Flatts, the theme song to “Cars.

But the memories are all Estis has left of her son these days. Christian’s happy, joyful life came to an abrupt end Aug. 13, 2008, just months before his fourth birthday, when his grandmother unknowingly left him strapped in his car seat for 10 hours on a hot summer day outside her office.

It’s a terrible tragedy that happens far too often: An average of 30 children die in hot cars each year, or about one every nine days, since 1990, according to statistics provided from kidsandcars.org, a national non-profit child safety organization. Texas leads the nation in hot car deaths with 111 since 1990, well ahead of Florida with more than 75 cases and double those in California.

More than 110 children have died of hyperthermia in Texas since 1990, according to KidsAndCars.org, more than any other state in the nation.

More than 110 children have died of hyperthermia in Texas since 1990, according to KidsAndCars.org, more than any other state in the nation.

There have been five deaths in Texas this year alone, including a 2-year-old boy who was left in a church parking lot in Dallas while his parents attended a service inside. The boy’s father later found him around 3 p.m., with outside temperatures pushing 100 degrees.

With the staggering number of children left in cars, Ravi Maini, a lieutenant with the Cy-Fair Volunteer Fire Department, says their deaths can’t be the result of malicious intentions.

“That’s something accidental. Most people are quick to judge and say, ‘I would never do that, that’s a bad parent,’ but sometimes people make mistakes,” Maini said.

Such is the case for Estis’ family: A momentary memory lapse by Estis’ mother, Donna, led to Christian’s death.

“I didn’t lose my son because I didn’t care,” Estis says. “I wasn’t an irresponsible parent. I trusted the one who raised me properly to take care of my child, and unfortunately, she had a misstep. She’s not bad, either.”

The day Christian died, Estis woke up late for work. She had been up studying for a math final well into the late night hours the evening before. She was in a rush to get to the office by 8, so she asked her mother to take Christian to day care and to pick him up because she had a math final that evening.

Estis remembered helping Christian get dressed. He, too, was tired after staying up late because of a pizza party with his cousin. She kissed her sleepy son on his head, said one last “I love you” and raced to work.

She never imagined that would be the last time she would see him alive.

How can someone forget a child?

It can happen to anyone. It happens to doctors, judges, rocket scientists, college professors, to the people we trust most as a society with our children—principals, teachers and day care workers—to mothers and fathers who take all precautions to protect their children.

“You look into some of these parents and they’re the best people, pillars of our society,” says Janette Fennell, founder and president of kidsandcars.org. “You don’t want to find out the hard way that this can happen to anyone.”

There have been more than 755 children who died in hot cars in the U.S. since 1990, according to data provided by kidsandcars.org. 2010 proved to be the most deadly year with 49 deaths, 13 of which were in Texas.

Dr. David Diamond has studied the inner workings of the human mind since 2004—specifically how our brains allow us to commit such a horrific act as forgetting a child in a hot car. Diamond is a neuroscientist and professor with the University of South Florida who coined the term “forgotten baby syndrome,” the mental process that leads to people to forget.

Diamond says it centers around two systems in our brains: habit memory and prospective memory. Habit memories, he says, are based on actions that are performed on a day-to-day basis that become second nature. It’s how we can drive home from work without much thought. Prospective memories, he says, are the preparations we make to carrying out an act, such as planning a stop at the store on the way home from work.

There’s an entire science behind it, the inner workings of our minds, but when it’s all stripped down, Diamond says it’s a matter of our habit memories, the routines we run every day, overruling our prospective memories, the added steps we’re not accustom to. Forgetting that extra step is as easy as walking to your car thinking about your day, or answering a phone call during the drive that shifts your mind’s gears, allowing the habit-memory system to take over. During the transition, Diamond says our minds can create a false memory of completing the task.

Sadly, Estis’ case is far too common. Parents have been forgetting their children in hot cars for nearly 30 years, according to kidsandcars.org. It’s an unthinkable tragedy that began to spike in the mid-1990s, a time when experts recommended car seats and young children be moved to the backseat due to the potential deadly dangers of passenger-side airbags.

The effects of the new laws meant to protect children ultimately put them out of sight and, in the most extreme cases, out of mind for parents.

What exactly happens to someone in a hot car?

In a hot, sweltering parking lot on another baking July summer afternoon, Ravi Maini and Andrew Nix prepare for an experiment that is crazy in every sense of the term. The two Cy-Fair Volunteer firefighters are going to lock themselves in the cab of a fire engine with no air conditioning and the windows rolled up for as long as their bodies will allow, all to raise awareness for children and pets that are left in hot cars.

Medics stand outside the truck as it cools to a frosty 65 degrees before Maini kills the engine.

Instantly, the heat cuts through the cool cab and the painstaking experiment begins. The first 10 minutes are the worst, Nix says, as temperatures quickly rise from 65 degrees to nearly 100. The air grows thick, stagnant and hot, making it harder for the two firefighters to breathe. Nix, sweat soaking his brown hair and dripping down his face that is growing more pale by the minute, says he felt nauseous and light-headed. Maini can’t quite describe it other than to say he didn’t feel quite himself.

“Normal function, normal thinking, thought process, everything slows down a little bit,” Maini says. “You turn a little slower, you react a little slower.”

Within 20 minutes, inside temperatures rise to 104 degrees, with surface temperatures on the dashboard climbing well above 130 degrees. Outside the cab, under partly cloudy skies, temperatures climb into the mid-90s with a heat index well into the mid-100s.

The firefighters’ core body temperatures are climbing to 103 degrees—a degree shy of temperatures that can prove deadly.

After 35 minutes, the experiment is called off and the two open the cab doors and slowly step out into the hot summer air that brings almost instantaneous relief. Paramedics quickly surround them and cover their necks with cold towels and rush them inside an ambulance to lower their core body temperatures.

“When I was sitting in there, I felt maybe I could do a few more minutes and be OK, but as soon as I stood up, as soon as I got out, it just him me like a brick wall,” Nix says.

“It was a terrifying experience.”

For children, it’s even worse

Children’s bodies aren’t as developed as adults, and their ability to cool off—or lack thereof—makes them nearly five times more susceptible to the heat.

Within moments, heat exhaustion sets in: They start sweating, their heart rate increasing, their breaths drawing faster.

“It’s their bodies’ way of compensating to the heat,” said Dr. Robert Lapus, medical director of the pediatric emergency center at Children’s Memorial Hermann Hospital. “After that, they can no longer compensate.”

When their bodies succumb to the heat, hyperthermia, more commonly known as heat stroke, takes effect: a horrific process of respiratory, kidney and organ failures, seizures and cardiac arrest.

‘I lost what is most important to me’

“You would think you would have a feeling your kid is gone,” Estis says. “I didn’t have any feeling or idea.”

Who can blame her? How could she expect her 3-year-old son is dead at the hands of her mother—the one who played with Christian and made him laugh, the one who taught Estis how to be a mom?

“I think if it’s possible, if there was one person on the planet who loved him more than I did, it was her,” Estis says.

She learned of Christian’s death from a grief counselor in the parking lot after her math final: Christian was never dropped off at day care and he died in the back of her mother’s car.

It took a moment. Of course it did. What parent can immediately comprehend their child is no longer alive? Estis says her mind snapped: She immediately thinks about driving her car into a grove of trees or grabbing her gun in the glove box to end her life. She’s placed into the back of a police car before she can make any rash decisions. She curls in the fetal position and cries, a flood of tears for the loss of her son.

As the car drove south to the Webster police station, Estis learned her mother had been arrested and is sitting in jail. Her mind snaps again, she says; in that moment, all she wants is her mother by her side.

“I’ve had people tell me that they couldn’t forgive their own mother, but they don’t have the relationship we have,” Estis says. “I knew my mother would not have hurt my child on purpose. And instantly I needed her by me.”

Her mother was never formally charged—Estis believes police were awaiting her reaction whether to press charges. The case was submitted to a grand jury, which later decided not to indict her.

The pain of losing Christian traumatized Estis for years. She refused to leave her home. She developed agoraphobia, she says, a fear of the outside world, and post-traumatic stress disorder. She learned to make money from home, had friends and family run her errands. Outside, the world is a haunting place that killed her son, while inside her home she felt safe and could protect her newborn daughter, Bailey, whom she gave birth to a year after Christian died.

She didn’t plan it that way. Her fear and trauma of Christian’s death ran so deep that while pregnant with Bailey she planned to give her up for adoption. She feared that she wouldn’t be a fit parent, that she couldn’t properly raise another child. But Bailey was a blessing, she learned, a gift from God to help her through her pain.

That didn’t make raising Bailey any easier. Fear still gripped at her. She didn’t let Bailey play or interact with other children, and Bailey only saw the inside of a car maybe six times in those years, Estis says, the fear too paralyzing to risk losing another child.

Until, one day, she had enough.

“That’s no way for a kid to grow up. You can’t show them to have a backbone when you don’t have one,” Estis says.

Gone, but not forgotten

Her life doesn’t move at such a fast pace these days; losing a child has a way of putting life in perspective.

She’s still cautious and worries about her daughter. She refuses to let Bailey ride the bus or in day care vans. She insists on taking Bailey to and from herself, even if she risks being late. She’s implemented a system with her family and friends that if Bailey rides with them, they have to send her a picture when they arrive letting her know Bailey made it safely.

She’s also started a security and investigations company that, among other things, specializes in training security guards to be on the lookout for children left in hot cars during their patrols.

Dee Dee Estis looks through a photo album of photos of her 3-year-old son.

Dee Dee Estis looks through a photo album of photos of her 3-year-old son.

She thinks back: Christian would have been 12 this October.

“That’s one of the hardest things for me to keep track of, because, for me, he will always be 3,” she says.

She still thinks about the what ifs of that day: What if she hadn’t been so worried about being late to work, what if she took Christian to day care herself?

“Thinking about the ifs is how you think about ways to prevent it,” she says. “You just don’t let them get you down.”

She will never forget her son’s death and the joy he brought her in his three short years. As she talks about Christian, she pauses…her eyes glance at the pictures hanging on her walls.

There, her brown-haired, blue-eyed boy smiles back at her, with the memories that will never be forgotten.