Last Updated Oct 18, 2017 10:42 AM EDT
For the first time we're hearing from the man who potentially helped save hundreds of lives during the Las Vegas massacre. was the first person to confront gunman Stephen Paddock on the 32nd floor of the Mandalay Bay hotel.
"I'm doing better each day. Slowly but surely, just healing physically and mentally," Campos told Ellen DeGeneres in an interview that's expected to air Wednesday.
Campos said he was checking an open door on the 32nd floor when he noticed something was wrong, reports CBS News correspondent Vladimir Duthiers.
"There was a metal bracket holding the door in place," Campos said.
"When you saw that, did you think that's weird, why would somebody put brackets on a door?" DeGeneres asked.
"That's just out of the ordinary," Campos said.
He called security dispatch and was walking through that door outside the gunman's room when it slammed behind him, possibly alerting the shooter as he moved down the hallway.
"As I was walking down, I heard rapid fire and at first I took cover. I felt a burning sensation. I went to go lift my pant leg up and I saw the blood. That's when I called it in on my radio that shots had been fired," Campos said.
Security dispatch sent building engineer Stephen Schuck to check on the door. He was halfway down the hallway before he saw Campos.
"Jesus, he leaned out and he said take cover, take cover and yelled at me and within milliseconds, if he didn't say that, I would've got hit," Schuck said.
"Because he was still shooting, so you would have been hit if he hadn't told you," DeGeneres said.
"Yeah, I wasn't even fully in cover and they were passing behind my head and I could feel the pressure," Schuck said.
Paddock killed 58 people that night. If not for Campos, that number could have been higher.
"I just want to mention all the people that assisted that night, whether it was Metro, the FBI, the community especially coming out together to help everyone in need. Everyone came together to help that night even in the darkest hour," Campos said.
Campos' quick thinking also saved the life of a woman who nearly walked into the gunfire when she came out of her room into the hallway. At the end of the interview, DeGeneres said both men turned down cash rewards from the show, but she did surprise them with tickets to their favorite football teams and a donation for $25,000 dollars for the Las Vegas victims.