The former principal of Columbine High School says he recites the names of 13 victims who were killed in the tragedy every morning.
Frank DeAngelis, known to his students as “Mr. De,” was principal at Columbine High School when the massacre took place 20 years ago this week.
Now retired after 35 years at Columbine, he has written a book, "They Call Me 'Mr. De': The Story of Columbine's Heart, Resilience and Recovery." All proceeds go to charity.
He says the memory of the 12 students and one teacher killed that day continues to inspire him.
“Each morning I wake up, I recite their names because they helped me through the most difficult times of my life and they'll be with me for eternity,” he told Inside Edition.
This week, tragedy nearly struck Colorado schools again as cops hunted for an 18-year-old who planned to shoot up a school in the state. She was found dead of a self-inflicted gunshot wound Wednesday.
DeAngelis said that if you see a red flag in an individual, say something to authorities.
“I tell parents, I tell community members and school officials, if you have students, your kids, that are infatuated with the two gunmen from Columbine High School, that's a red flag,” he said.
He added: “If you see something, say something.”
DeAngelis also added that he encourages kid to take care of each other.
“If they see their friends are struggling, they have to be able to talk to someone so we can get them for support," he said.