An Alabama woman's infant daughter remained locked in an SUV for four grueling hours on Wednesday, as the sweltering 90-degree weather turned the car into a 127-degree oven. By the time the mother realized the mistake she'd made and rushed outside to save her daughter, it was already too late.

Katie Luong, 31, says that no one can blame her for what she did more than she already blames herself. Gabriella Gi-Ny Luong, known to her family as Ella, was discovered around 1:20 p.m. still strapped to her car seat inside the Lexus parked beside the family's nail salon. Luong and her husband had been trying to conceive for years before finding success in Ella.

"I want to tell everybody that I wish I was in that car seat, not her," the weeping 31-year-old mother told Birmingham News. "If I had to die for her to live, I would have done that."

Luong's fatal memory lapse came as the result of stress-filled weeks leading up to Wednesday. A co-worker of hers had just committed suicide — the first death she had encountered in her life, she said — and a family friend had recently been hospitalized for a stroke. She was supposed to drop Ella off at the babysitter's before work at 9:30 a.m.

When Luong never showed up, the babysitter called to ask if Ella was sick. By then, Luong and her husband realized what she had done and rushed outside to save their daughter.

A nearby business owner tried to revive the unresponsive Ella, and then paramedics, too, on the way to the Children's of Alabama hospital, but the damage had been done. Ella was pronounced dead soon after arrival.

"Please ask anyone who knows me," pleaded Luong, who had planned on throwing Ella's first birthday party at a nearby park on Sunday. "I have never done anything wrong in my life."

Luong's story echoes the hundreds of cases of children who were accidentally locked inside a car on a hot day. One estimate pegs the heat stroke death toll at over 600 cases between 1991 and 2011.

"There is no safe amount of time to leave children alone in the car," said Dr. Nathan Allen, an emergency medicine doctor at the University of Chicago. "Kids are more susceptible and at higher risk for heat-related illness and injury than adults because their bodies make more heat relative to their size and their abilities to cool through sweating are not as developed as adults."

Even with the windows down, Allen says, the car's internal temperature can become far too hot for a child.

Heat stroke can occur when the body's internal temperature exceeds 104°F. The brain's temperature control becomes overwhelmed, causing the person to feel dizzy, disoriented, agitated, and confused — even inducing seizures, loss of consciousness, or death.

"When you hear just a few details, you can judge quickly but it's different when you know someone's heart and hear their hurt,'' said Allan Murphy, Luong's church pastor, whose own daughter died of drowning 14 years ago. "It was a tragic thing that happened. A human tragedy."