MASON, Ohio—Karen Osorio was alarmed when her husband called at the end of the day to say their 15-month-old daughter wasn’t at the day-care center when he went to pick her up.
Then she considered a horrifying possibility. She sprinted to the parking lot of her office at Procter & Gamble Co.
“That’s when I saw her, she was in the car,” says Ms. Osorio, a senior scientist at P&G. While she had been working in the office all day, her daughter, Sofia, had remained buckled in her car seat, having never been dropped off at the day-care center.
“My baby just died, my baby just died,” Ms. Osorio told a 911 dispatcher between gasps. “I left her in the car, she’s dead.”
Sofia Aveiro was found dead after nine-and-a-half hours in the back seat of her mother’s car on Aug. 23.
Ms. Osorio was nearly overwhelmed by grief. “I have never questioned faith before, until that moment,” Ms. Osorio says. “You’re starting to question hope and you can get very dark.”
As the days went by, Ms. Osorio says, she felt a calling. The best way to cope, she decided, was to take action to prevent a similar tragedy from happening to others.
Hot-Car Deaths
Vehicular heatstroke deaths of children increased in the 1990s as states required that car seats be placed in the back to avoid front-seat air bags.

Vehicular heatstroke deaths of children in the U.S.
50
fatalities
40
30
20
10
0