(CNN)--A Colorado man used a heartfelt Facebook video to find his first responders after collapsing at a half-marathon in Florida.

Amy Smythe, 39, of Neward, Delaware, could not stop thinking about the man who had collapsed nearby, mere feet from the finish line of the Key West Half Marathon last week. She had just set a personal record, beating her previous best by 20 minutes.

"It was fate that I had finished early," she said.

Bill Amirault, 44, of Colorado Springs went into cardiac arrest as he was rounding the final corner of the race. Smythe, a nurse in the cardiovascular unit at Christiana Care's Christiana Hospital, wasted no time.

"I think my instincts just kicked in," Smythe said.

With two other strangers who were also medical professionals, she began administering CPR until paramedics arrived and shocked his heart into a normal rhythm.

With the crowd growing, the paramedics carried Amirault away, out of Smythe's sight. She "couldn't stop thinking about him," she said, but didn't know his name or where he lived.

Smythe checked the local news that night. She checked the papers. There was an article about the marathon in the sports section but no mention of the incident. Nothing had been posted to the marathon's website, either.

Amirault, who had been airlifted to Mount Sinai Medical Center in Miami, was also checking the news as he recovered, searching for any indication of who had kept him alive until the ambulance arrived.

That's when Amirault, who "never really used social media," had an idea: Make a Facebook video go viral.

"I'm hoping you can help me find the person or people that saved my life this past weekend," he said in the video, shot in his hospital bed at Mount Sinai.

The video, posted January 20, has been viewed 1.4 million times and shared more than 27,000 times, and it's received over 1,600 comments from people, including other nurses, who were determined to help him find the people who saved his life.

His video ends with an urge for people to learn CPR. "Those three minutes were so critical," he said.

Less than 24 hours later, he had identified the people who had performed CPR on him as resident nurse Smythe, a neonatal nurse and an anesthesiologist.

"My girlfriend ... called me: 'You gotta check Facebook out!' " said Smythe.

"I was just so overwhelmed," she said. "I immediately was in tears."

Both Smythe and Amirault described their initial phone meeting as joyful, and both said their chance meeting has made them appreciate the little things.

"How it all came about with Facebook is just crazy for me," Smythe said.

"It's nice to have something positive on the internet right now," she added.