Former Miss Las Vegas thanks retired firefighter who saved her and her mother's lives

— -- A former Miss Las Vegas winner got the chance to thank the retired firefighter who saved her, her mother, her sister and two girlfriends when a gunman started shooting onto the crowd at a music festival they were attending on the Las Vegas Strip Sunday night.

"My mother is alive because of you," Paige Melanson, who was Miss Las Vegas 2016, said between sobs to retired Los Angeles firefighter, Don Matthews.

Melanson was with her mother, Rosemarie Trautman-Melanson, her younger sister Stephanie, and two friends for the Route 91 Harvest Music Festival across the street from the Mandalay Bay Resort and Casino.

During the concert, a gunman identified by police as 64-year-old Mesquite, Nevada resident Stephen Paddock, opened fire and sent 22,000 terrified concertgoers running for their lives. The attack killed at least 59 people and injured more than 500. Paddock was found dead on the 32nd floor of the Mandalay Bay hotel when authorities entered his room.

When the gunfire started, Melanson said there was instant chaos.

"I don't know if I was pushed to the floor or everybody just started falling over, but everybody got down and I was facing away from my mom," Melanson told ABC News' Juju Chang in an interview for "Nightline." "So by the time I turned around to gather and see who was around me, I had realized my mom wasn’t just laying there like we were. She was still and her face was face down in the grass, and so we had known something was wrong."

Her sister immediately started screaming, Melanson said. As they rolled their mother over onto her back, she said Matthews, a total stranger, rushed over to them and insisted they leave their mother, who had been shot in the abdomen, with him so they could run to safety.

"He told us that we have to go if we wanted to live, that we needed to go and save ourselves," she said. "And the fact that he was a retired firefighter, he was trained to help people, and he promised us that if we left that he would stay with my mom.

"I looked into his eyes and he said, 'You need to go,'" Melanson added.

Matthews later told her that he needed Melanson and her sister to leave so that their mother could focus on her breathing and not worry about their safety.

Paige Melanson said she then grabbed her sister and her sister's boyfriend and ran, jumping over fences and barricades until they got to the nearby Tropicana Las Vegas hotel on the strip. Matthews said he and a few others helped get their mother to an ambulance and he went back to help others who had been shot.

"I was so torn between staying there with your wife, your mom, and trying to protect my girlfriend who was five feet away, and honestly ... I wanted to get up and run so bad so many times," Matthews told Melanson and her father. "I just couldn't do it. I promised your daughters that I would be there with her."

Paige Melanson said she didn't even realize she had been shot in the elbow herself until after they got to the hotel, where she said another stranger wrapped her arm in a cloth napkin.

"I saw that I was covered in blood," she said. So my first reaction was, 'Where's it coming from?' And I looked over and I saw the flap over my skin and I kind of had just exploded. ... There was blood all over my legs, dripping all the way down my arms that was everywhere, and I didn't care because the second I saw my mom ... I didn't feel my arm at all."

Meanwhile, their father, Stephen Melanson, was at home, getting texts from his daughter and Paige's sister, Stephanie.

"[The music festival] was a Mother's Day present from my other daughter Stephanie and says she's having the time of her life," Stephen Melanson said.

But then later, he started getting texts saying, "Mom is hit" and "Mom is down."

"I was in a daze," he said. "I wasn't quite sure if I was comprehending it or not."

Paige Melanson, her father and their family were in a panic trying to locate Rosemarie. When the finally found her 11 hours after the shooting, she was at Sunrise Hospital in Las Vegas. She had survived. Melanson said her mother has undergone two surgeries so far and her prognosis looks good.

She will never forget the man who saved their lives.

"He put his own life at risk," she said. "He didn't have to this."