A man who witnessed the harrowing collapse of a 12-story condominium tower outside of Miami helped rescue a young boy who was in the rubble.

“As I got closer, I could hear someone making a noise and screaming. I approached the building and climbed into the rubble and I heard him say he was over there and I could see his arm sticking out through the rubble and waving his hand, “said Nicholas Balboa, a man from Phoenix, opposite CNBC’s “The News with Shepard Smith” on Thursday night.

“He just said, ‘Please don’t leave me, please don’t leave me.’ I told him we weren’t going to leave him, “said Balboa. “It was me and someone else. So we were there and felt like we could reach him. It didn’t feel right to just leave him, especially to hear that his voice was just so young.”

Balboa was in Surfside, Florida to visit his father when the Champlain Towers South building collapsed early Thursday. Authorities were called about the collapse around 1:30 p.m. ET, according to NBC News

99 people were still missing as of Thursday evening, at least one person was confirmed dead.

Rescue teams have searched the wreck for signs of life for more than 17 hours, using canines and sonar to aid in the search. They rescued 37 people alive from the rubble.

Hear and follow The News with Shepard Smith Podcast, CNBC’s daily news podcast that offers comprehensive, impartial coverage and perspective on the most important stories of the day, on Apple, Spotify or your favorite podcast platform.