On April 20 students and staff at Columbine High School near Littleton, Colo., marked the first anniversary of the worst day of their lives—the day when two of the school's 2,000 students, Eric Harris, 18, and Dylan Klebold, 17, went on a shooting rampage that killed 12 students and one teacher and injured many others before the two turned their weapons on themselves. In the months since the tragedy, the Columbine community has been jarred by continuing aftershocks, including the suicide of the mother of one of the injured victims and the shooting death of two more Columbine students in an incident at a nearby sandwich shop.

Helping to close the wounds is Columbine principal Frank DeAngelis, 45. Known affectionately as Mr. D, he rushed back into the school during the shooting to help evacuate students. A Denver native who came to Columbine as a social studies teacher in 1979 and became principal in 1996, DeAngelis was criticized by some parents at the time of the shooting for being out of touch with students, largely because he denied the existence of a Trench Coat Mafia. (According to The Denver Post, a soon-to-be-released sheriff's report indicates that there was no such organized group.) Since the murders, he has counseled hundreds of grieving students and served as a symbol of Columbine's resolve, even while coping with his own feelings of loss. "This year I attended more funerals than in all my 45 years," says DeAngelis, who is married to Cheryl, a manicurist, and has a son, Bryant, 25, and a 16-year-old daughter, Hayley, a junior at another high school. Staff correspondent Vickie Bane sat with DeAngelis to discuss the pain and hope that filled what he calls "the saddest, most difficult year of my life."

One year ago on April 20, I remember my secretary running into my office and saying, "Frank, there has been gunfire," and me saying, "You're kidding. Go back in and call 911." I took about 10 steps out of the office and saw a person coming down the corridor with a shotgun, shooting and blasting out windows. I kind of froze, until I heard some students laughing and joking down an adjacent hall. I realized it was some girls coming out of the locker room on the way to PE class, and hearing them caused me to react. People say I saved the lives of children, but these children saved my life, too.

At that point I went hurriedly down the hall, away from the gunman. I was walking, not running, because I didn't want to panic, and all I kept thinking was, "We need to get to a safe place." I rounded up the girls and took them to the gym and locked them in a storage closet while I went outside to see what was happening. I saw students running from the building and a strobe light going off. I realized the gunmen were not on our side of the building, so I went back in and got the girls out safely. I can remember standing on the street and seeing the kids coming out of the buildings crying. It was awful. I felt guilty because this was my high school. People had entrusted me to run it, and I felt I had let them down. But in a day of terrible moments, the absolute worst was knowing we lost some members of the Columbine family—13 in all, I found out the next day. I never envisioned the impact it would have on the country and the world until much later.

In the weeks that followed, I was often asked how I could not have been aware of the Trench Coat Mafia, this group of kids that supposedly harassed students. And I would answer that the reason I didn't know about it was that it didn't exist as an organized group. I even asked the teachers, "Am I out of touch? Was there this group that terrorized the school?" And they said, "Frank, we didn't see it."

I was more worried about being there for the students who needed me. What scared me were the kids who refused to open up to anyone. I can remember parents calling me, saying, "Frank, the kids are shutting us out." I made a point of addressing the students and telling them, "Your parents need you as much as you need them. I want you to go home and hug your parents and tell them you love them."

Then last Aug. 16, the kids finally came back to school for the first time since the shooting. It brought tears to my eyes to see them walk through the doors, to see these students who had been shot and battled back. They had the courage to return, and that gave me the courage to carry on. All told, very few kids left Columbine because of the shooting. We didn't have a lot of staff members quit either. The students and teachers had every reason to go somewhere else, and they came back. They didn't want to quit on Columbine, and neither did I.

Things were going along well until October, when one student was arrested for making a threat against the school. Then the mother of one of the girls who had been injured in the shooting committed suicide. To make matters worse, in December, Time magazine somehow got its hands on the videotapes that Harris and Klebold made. A few days later we received an e-mail from someone who threatened to "finish the job." We had to close the school two days early for Christmas vacation and postpone final exams. That was one of the real low points of the year because no one expected it. At a point when we were taking giant steps forward, suddenly we took giant steps back. In all of this, it has been very difficult to think about forgiveness. The act those boys committed has simply caused too much pain.

We began the new year hoping for more healing, but then, on Feb. 14, I heard that there was a shooting that may have involved some of our students. I pulled into the shopping center a couple of blocks from the school, and I saw the crime scene with all these sheriffs and reporters. It instantly brought back a lot of memories. It was at that point that I found out a couple of our students had been killed at a Subway sandwich shop. [Police are still investigating.] Once the other students found out, we were afraid that, emotionally, it was going to cause havoc. We wrote a statement that was read to the students, and then they just got up and left their classrooms. I was in the hallways when they came out crying and hugging each other. I said to myself, "How much more hurt can these kids and this community go through?"

That's why I was so anxious about April 20, the one-year anniversary. That morning we had a private 90-minute ceremony for staff and students, and what really got me emotionally was when a lot of kids who had graduated last year came back for the day. Many of them had We Are Columbine shirts on. I went to the gym for the ceremony, and I started my speech by reading the names of the 13 people who died. I looked into the audience, and I saw the tears. Afterward a student sang "Amazing Grace," and that was just phenomenal. Later a teacher told me that during the song I had tears running down my face.

Maybe some people are thinking that once that one-year anniversary is over, we're going to have some closure. But that's just not the case. People ask me, "Have things gotten back to normal yet?" The fact is we will never get back to normal, to where we were before April 20. You just go to bed and hope that the next day, when you wake up, things will be a little bit better.

Seeing people smiling, seeing people healing, that really helps. To walk into the cafeteria and see kids being kids, I get so much pleasure out of that. I'll walk into a classroom, and kids will say, "Hey, Mr. D, how you doin'?" or they'll stop and give me a hug, and that's what keeps me going. There is a reason things happen, and although I may never know that reason, I have a lot of hope for the future. I look around and I think we're going to make it. I think we're going to be okay.