Shon Liles, a 14-year veteran with the department and fitness, had recently completed a fitness test that he helped create.
But within seconds, he was in cardiac arrest. His fellow firefighters were suddenly faced with shocking their good friend's heart to keep him from dying.
"The last thing I remember was one of my firefighters over the top of me, doing compressions and hearing the AED charging up to shock me," said Liles, 39.
Liles is now recovering at home, but says doctors have told him he was seconds away from death.
He was hospitalized for a week, and his fellow firefighters and fiancée, Amanda, were by his side. Liles was determined to make his May 23 wedding date.
"I told my fiancée I stayed alive just so I could marry her," said Liles.
A defibrillator is now implanted in his chest.
He returned to Firehouse 1 on Friday, where he built a career and nearly lost his life, to thank the guys who had his back.
"Those guys mean the world to me," said Liles. "I never thought I'd be in a situation where they'd have to save me…they stepped up and did what they do best. And I'm eternally grateful."