new york city last night, a dramatic rescue took place at a hospital. The backup generators there also failed. Tiny babies rushed out. Oxygen pumped by hand. And our david muir was there overnight... See More
new york city last night, a dramatic rescue took place at a hospital. The backup generators there also failed. Tiny babies rushed out. Oxygen pumped by hand. And our david muir was there overnight into the early morning hours. David? Reporter: We're still here tonight, diane. Nyu medical center is the hospital in question. I wanted to show you behind me if you look up you can see it's still pitch black after those generators failed less than 24 hours ago. It was at that moment the re respirators went down, and elevators. They turned to cpr bags to pump the air in themselves, toast tiny lungs to keep the babies alive. When we arrived all you could see was the outline of the hospital against the darkened sky. A lone flashlight up in one of the hospital rooms there as doctors and nurses rushed from patient to patient. Out front ambulances and images from my iphone as we approached the hospital. 1 of nearly 300 patients one by one brought out and taken by safety. From the sky the ambulances lined up around the block from all over the city and we're learning more tonight about the moments the lights went out, the moment critical machines and respirators stopped. This young doctor right there. Making sure theient was on ventilators. Reporter: The babies. The babies, yes. Reporter: Their first concern, babies in intensive care, 20 of them. This nurse holding one of those plastic bags and doing the work of the respirator her self-. All the nurses were doing what's called bagging the air, squeezing bags of air into those tinily lungs, cradling the babies and carrying them nine floors down. Another baby rushed out dwarfed by the size of the gurney. Once outside the bag replaced by oxygen brought in by the paramedic. An entire team surrounding one baby and a hospital source telling me that's what they did the moment was cut off dividing up into teams surrounding one patient at a time carefully bringing them down a darkened stairwell carrying them on plastic sleds rushed in by the paramedics. Flashlights all they had to see their way. There were a bunch of people that would go with each patient, carry them down the stairs physic physically. Reporter: They were pull ed out. At 10:00 a.M. In the morning you can see still see a line of ambulances all the way up the street. This operation has been going on for 12 hours now. You can see them lining up at the front entrance of the hospital here as they carefully bring the patients down. And late today, 15 hours after those evacuations began, they were done and the president and one of those heroic nurses and newborns. During the darkness I saw what's brightest in america. Nurses at nyu hospital caring for fragile newborns to safety. Reporter: We know that more than half dozen area hospitals took all of the patients from this one hospital alone, diane, and one more extraordinary note tonight, we learned that at least four of the women who left this hospital were in labor and at last check two of them have given birth, remarkable at this hour it appears that everyone taken from this hospital, diane, is okay tonight.
This transcript has been automatically generated and may not be 100% accurate.