SALT LAKE CITY (AP) — As four Utah police officers approached an overturned car discovered below a bridge in an icy river, they heard a woman's voice asking softly for help.

When the foursome flipped over the midsized car, they discovered a 25-year-old woman dead in the front seat. The only other passenger: an 18-month old baby girl in a back car seat, unconscious but alive.

A firefighter jumped into the river and cut the straps, freeing the blond baby girl who was wearing only a flannel onesie and no hat or gloves.

Officers formed a line in the river and handed the cold girl to one another until she was on the shoreline and in emergency workers' arms. They rushed her to an ambulance and performed CPR, Spanish Fork Police Officer Tyler Beddoes said Monday, two days after the crash.

Lily Groesbeck is in stable condition and improving, according to hospital officials. Beddoes, who spoke with the family, said the baby is opening her eyes and doing well.

Nobody knows exactly how the infant survived hanging upside down for nearly 14 hours in her car seat with no food or water. As she dangled, icy water rushed just below her head through broken car windows as the vehicle sat perched on the bank and rocks. The temperatures were near freezing throughout the night and through the morning.

"It's heartbreaking. Was she crying most the night?" said Beddoes, a 30-year-old father of two. "It's a miracle. . . She was needed for sure elsewhere."

And that voice? Beddoes said he and the three officers talked later and concurred they all heard the same thing. They can't explain it, but have no doubt they heard it.

"That's the part that really sends me for a whirl," Beddoes said. "I'm not really religious, but that's what you think of."

Police believe the accident occurred when the baby's mother, 25-year-old Lynn Groesbeck, struck a cement barrier on a bridge and careened into the river late Friday in Spanish Fork, about 50 miles south of Salt Lake City.

She was driving to her home in Springville after visiting her parents in Salem, Spanish Fork police Lt. Matt Johnson said. Investigators don't know what caused the crash, he said. There were no skid marks or signs of mechanical failures in the car.

Police don't suspect drugs or alcohol as a factor but are awaiting toxicology test results. Maybe Lynn Groesbeck was tired or distracted, Johnson said, adding authorities weren't ruling anything out.

Lynn Groesbeck was enrolled at Provo College with a goal of becoming a medical assistant, her sister Jill Sanderson told the Deseret News.

Even though the road that goes over the bridge gets plenty of traffic, no one saw the wreck because the cement barrier obstructed the view of below, Johnson said. If the fisherman didn't choose that river that morning, it could have been several more hours, he said.

Sanderson wasn't available for comment Monday but she told the Deseret News newspaper and KSL-TV of Salt Lake City on Sunday that Lily is doing remarkably well considering what happened.

Beddoes said the family has thanked him and the other officers for helping to save little Lily. As he recalls the events of those chaotic moments, on a frigid but sunny day, Beddoes still can't believe the girl survived — and still can't make sense of that undeniable voice coming from the car.

"We all got together and we all heard the same type of thing," Beddoes said. "We just can't grasp what we were hearing."