Transcript for Mystery Surrounds 18-Month-Old Lily's Miraculous Survival
Finally tonight here, America strong. The miracle baby near Salt Lake City and the fishermen, the police officers, the doctors and nurses who helped save her. 911, what is the address of your emergency? There's a car in the river -- What kind of car. There's a person inside. Reporter: The voice of a fisherman calling 911 Saturday often, just 50 miles south of as a matter of fact Lake City. A car upside down, it had been there for hours. Officers rushed to the scene. They were not expecting any survivors. I said, was I the only one that's hearing this, thinking I was hearing things. The other officers heard the same thing. A voice saying "Help us. Help me." Reporter: They heard a voice. Tonight, sun sure who it was. Inside the car, a young mother. 25-year-old Jennifer Groesbeck who would not survive. At first, they did not know there was someone else. We were able to flip that vehicle up onto its side. That's when I noticed that there was a baby in the backseat. Reporter: Little lily, just 18 months old. Upside down, hanging from her car seat for 14 hours. Just above the water. The thing I remember the most is that baby coming out and its eyes were just fluttering. Reporter: Lily was rushed to the hospital. If not for that fisherman, those office officers, who knows what would have happened to lily. Tonight, the hospital telling us shell's been upgraded to fair condition and is improving. And the family grateful tonight. Writing, "We are beyond thankful for the love and is up important. Lily's improvement is astounding. Right now, she's watching Dora and singing wheels on the bus with grandpa. Smiling and laughing. We're blown away by lily's progress." The rescuers who still don't know how that toddler survived. Or, how they got to her. How, I don't know. I mean, if it's adrenaline or what, but it was incredible. And it feels good. Feels good. We are all pulling for lily tonight. We thank you for watching here on a Tuesday evening. I'm David Muir. We hope to see you right back here tomorrow.
This transcript has been automatically generated and may not be 100% accurate.