ROCKVILLE, Md. (WUSA9)-- It was a very happy 32nd birthday for Michael Liu this year.
The Rockville man is thankful to be alive, after a frightening incident last May when he collapsed while jogging.
Four months after the incident, Liu finally had a chance to thank Heather VonKurtze, the stranger who helped save his life that fateful day.
Liu had been jogging and pushing his child in a stroller, when his heart sent him a message.
Liu went into cardiac arrest, and collapsed. Luckily, VonKurtze came to his aid and called 911.
911 operator Jeff Purcell walked VonKurtze through the steps to perform CPR, while Von Kurtze's 9-year-old daughter waited to meet paramedics.
VonKurtze described the events of that day as a "miracle".