Before Erica Nigrelli collapsed in a co-worker's classroom at Elkins High School in Missouri City, Texas, she was unaware how dire her condition was.
"Apparently I told her 'I feel very faint,' and I put my head down and essentially just passed out," the 32-year-old English teacher recalled.
Nigrelli, who was 36 weeks pregnant, technically died, said WMUR-TV.
"I opened the door and walked in and Erica was lying on the floor," said Erica's husband Nathan, also a teacher at the high school.
Erica's heart had stopped and co-workers began CPR and used a defibrillator to get try to get it working again. They kept Nigrelli alive until paramedics arrived, who then rushed her to a hospital. There doctors delivered her baby girl Elayna by emergency caesarean section.
Since Nigrelli's heart wasn't beating at the time, Elayna's was technically a postmortem delivery.
"There were two lives that were hanging in the balance the whole time," Nathan said.
But doctors were able to bring Nigrelli back to life. After Nigrelli had revived, they discovered she had an undetected heart defect, which is now managed by a pacemaker.
Elayna is now three months old and weighs nine pounds. Doctors said she's growing and thriving.
Says mom: "She's just a baby, a normal baby."
Check out the news clip of the amazing event here: