Carolina Panthers' Pro Bowl tight end Greg Olsen was in Nashville last week to deliver a keynote speech at a healthcare conference. As the 6' 5", 255 lb. former first round draft pick was walking back to his hotel, he happened upon something that he would call the "best thing I've ever witnessed."

What Olsen was describing was an in-progress marriage proposal. With a ring box in hand, Max Harvat was on bended knee just about to pop the question to his girlfriend Brooke Hartranft.

Olsen pulled out his phone and started filming.

“So I’m thinking, ‘I would imagine that this guy would love to have this on film.’ He was literally five feet from us. It was amazing,” Olsen told panthers.com.

After the proposal, Harvat got back to his feet and joyfully lifted Hartranft into the air.

"What did she say? Did she say, Yes? Olsen asked.

"She said, "Yes," Harvat screamed back, his voice echoing through the hotel complex.

"I've got it on video, dude," Olsen said. "I'm going to send it to you."

"You're my hero," said Harvat, not knowing at the time that he was speaking with the three-time Pro Bowler who happens to play for his favorite team.

"That was the best thing I've ever witnessed," Olsen said.

“When I stood up, I looked over and I started having a mini heart attack," Harvat told panthers.com. "I was like, ‘I’m 90 percent sure that’s Greg Olsen from the Panthers!’”

“Brooke looked at me and didn’t believe me,” Harvat said. “She just thought I was too excited and wasn’t seeing straight. But I’m like, ‘No, that’s him. I’ve seen him on TV and in interviews. That’s him!’”

On his Instagram page, Olsen explained that his instinct was to film the precious moment because he had wished he had a video of his own marriage proposal.

“He was really respectful," Harvat told panthers.com. "He didn’t want to steal any of the moment from us. He sent me the video and said congratulations and wished us the best.”

Check out the video on Olsen's Instagram page. It has been viewed more than 135,000 times and earned more than 36,000 Likes since it was posted three days ago.

Credits: Screen captures via Instagram.com/gregolsen88. Split frame: Greg Olsen (left) by Jeffrey Beall [CC BY 4.0], via Wikimedia Commons. Greg Olsen (right) by original: U.S. Army National Guard Photo by Sgt. Leticia Samuels, North Carolina National Guard Public Affairs/Released North Carolina National Guardderivative: Diddykong1130 and XxSuguSxX [Public domain], via Wikimedia Commons.