Nurses at the neonatal intensive care unit at Kings County Hospital spend their days helping premature babies survive and thrive.

News 12 Brooklyn's Naomi Choy Smith spent a day with one of them as she got the job done.

Iris Kaplan has been an NICU nurse for almost 40 years, she says.

"I love children, so I think that's where it started," she says. "And then throughout the years, saving younger and younger babies, it's like a miracle."

Her 12-hour work day begins at 8 a.m., when she takes pint-sized patients' vital signs and provides treatment.

"We're looking at the respiratory rate, the heart rate, if the blood pressure is normal," she explains. And she also checks for other things like how they're tolerating food.

And she says it's most rewarding when her tiny patients make progress. On Friday, a baby named Kiana was doing well enough that Kaplan could remove her breathing tube.

"You feel happy when you live and you did something good," she says.

Kaplan is one of almost 40 NICU nurses at Kings County Hospital. Between them, they care for premature babies 24 hours a day, seven days a week.