ST. CHARLES, Mo. — The clanking of hard work echoes around the clock at Main Street Gym in St. Charles.

But during a cool-down on the treadmill Memorial Day, a different sound caught Julie Meyer's attention.

"I heard some calling for help,” Julie Meyer said.

Across the gym, a man was down on the ground.

"The last thing I remember was being right here,” Steve Baker said, pointing at a leg machine.

Baker had no clue what happened to him.

"As we rolled him on his back it was clear to me that he had stopped breathing and his heart had stopped,” Julie said.

With 26 years of experience as a nurse, Julie knew just what to do. She started CPR and ran for the gym's AED, which had just been installed six months ago.

The device shocked a rhythm back into Steve's heart.

He had a pulse and he was breathing by the time firefighters arrived.

Steve and Julie and the firefighters who responded to gym met for the first time Wednesday

"I'm so happy for you,” Julie said.

“It's my guardian angel right here,” Steve said.

Julie recounted what could have easily been the last moments of Steve’s life.

“I don't think he would have lived without the AED,” Julie said.

Steve said he wouldn't have lived without Julie.

"If she wasn't here, who knows what would have happened,” he said.

He spent about a week in the hospital, and he's still getting used to life with a pacemaker, but his experience won't keep him away from this place for long.

“As soon as the doctor will clear me, I'm ready to get back,” he said.

There's a staggering statistic that shows just how lucky Steve is.

Nationally, the survival rate for people who have a cardiac event outside of a hospital is just six percent.

But AEDs, which are now in schools and airports and other public places, are helping to change that.

They have easy-to-follow instructions, and they're designed for people who aren’t experts.

It used to be too expensive for small businesses to afford AEDs, but this gym told has a lease-to-own deal that costs them less than $100 a month.