June 24, 2014 -- It's been seven years since Lyn Balfour realized she left her 9-month old son in the car while she was at work, mistakenly thinking her precious baby boy with was the babysitter. The boy overheated in the backseat of the sweltering car and died.
Balfour, an analyst for the U.S. military, realized her mistake too late. Now she's devoted her life to helping other parents who have lost a child by accidentally leaving a baby in the car, and fighting to change auto laws for better safety features.
"I'm honest with them," Balfour, 42, told ABC News. "It's one thing when you lose a child. It's completely different when you lose a child and it's your fault. The pain does not go away. It's something you learn to live with."
Every summer, stories like Balfour's emerge. This week a Georgia dad was charged with felony murder after leaving his 22-month old son in a mini-SUV on a day when the temperature reached 92 degrees by noon. Every year in the U.S., an average of 38 children die after being left in a hot car, according to the nonprofit Kids and Cars.
Balfour, from Earlysville, Va., works with the organization to reach out to parents who have accidentally left their children in cars. Some face murder charges and criminal trials, while others got lucky and realized their error before the unthinkable happened. Since 2007, when her son Bryce died, Balfour has talked to about 15 to 20 parents who have gone through similar experiences, she said.
"I always tell them, you're not a bad parent," Balfour said. "No one is going to judge you more than you do yourself. I know that I did not leave my son in the car intentionally when I left that day. People tell me I need to forgive myself -- I don't feel like I have anything to forgive. I made a mistake and it cost me my son's life. But I certainly didn't leave him in the car to go bowling or to get my nails done."
Janette Fennell, the founder of Kids and Cars, says parents like Balfour are uniquely suited to help other parents who have lost a child to hyperthermia after leaving him or her in the car.
"No one understands what you're going through except someone who has gone through this," Fennell told ABC News. "They don't understand how it could happen. We try to give them as much info as possible about how their brains work, some of the science behind it. At least a portion of why this is happening is because the kids are out of sight and out of mind. They're in a rear-facing car seat. Most of them are under one. Parents that first year are so sleep-deprived. Add all these things together and it really is a recipe for disaster."
She and Balfour are fighting to get auto companies to consider a feature to help exhausted parents to remember to check the back seat, perhaps motion or weight sensors, she said.
"The auto industry already knows we're human," Fennell said. "If you don't put your seatbelt on, you get a beep. If your key is in the ignition, you get a light. Today you can't even buy a car that doesn't turn your headlights off or warns you that they're still on. It just begs the question, who decided that it's more important to not have a dead car battery than a dead baby?"
Kids and Cars sometimes sends care packages to parents whose children have died after being left in a hot car. They contain letters from parents who have suffered the same experience, legal information, statistics and phone numbers for support.
Balfour takes it a step further, sometimes visiting parents at court if they're facing a criminal trial. She urges those parents to get involved with Kids and Cars.
"You can heal better and feel like there is a sense of purpose in the loss of your child if you get involved and help educate other parents," Balfour said.
It's turned into a sort of support group, which is ideal when typical support groups for grieving parents won't work.
"How do you walk into one of those groups and say, I want you to feel sorry for me? My son didn't die in a car accident, he didn't die of cancer, he died because I accidentally left him in a car," Balfour said.
Since she started speaking up about Bryce's death, parents she barely knows have been open about revealing their secrets -- quick to share the time they accidentally drove away with their son in a carrier on the roof of their car, or the time a busy mom left her kid in the car while she was at work, but kept having a nagging suspicion that something was wrong.
They are secrets the parents hadn't told anyone before Balfour.
"Has anyone ever walked up to you and said, 'Oh my God, I just left my kid in the car for an hour and a half'? No! Because they think you're going to call child protective services. There's this fear," Balfour said.
More parents than most people realize have experienced the fear of leaving their children alone in a hot car, Balfour said. Instead of stigmatizing parents who have made a fatal mistake, the goal should be to educate other parents on how to keep their kids safe.
"The worst thing people can do is think it can't happen to them," Fennell said.