A Missouri teenager was just doing some routine shopping at Walmart when a 11-month-old daughter suddenly stopped breathing in the store.

The woman was trying to revive her baby, but it wasn't working. That's when 17-year-old Abby Snodgrass jumped into action, using life-saving techniques she had learned recently in health class Hillsboro High School.

Snodgrass heard there was an emergency in the electronics department and immediately ran to the scene. 

Snodgrass explained to Steve Doocy this morning that she knew the CPR method for a baby was different than for an adult. 

"I put her on my forearm and held her head in my hand and started doing chest compressions with two fingers on her chest. Then I would flip her over onto her stomach, still in my arm, do the ones on the back, then flip her over again and do them again on her chest," she recalled. 

Snodgrass said thoughts were creeping into her mind about the possibility that the CPR would not work, but "pushed it out of her mind" because she knew she had to keep going with the CPR. 

Snodgrass estimated it was about a minute until the baby started breathing again. First responders said the baby may have died if not for Snodgrass' quick actions.

The teen, who is enlisted in the National Guard, said she wants to pursue a career as an ER doctor. 

Watch the full interview above.