(NBC News) After close to two decades on the job, the principal who was at the helm during the 1999 Columbine school shooting is retiring.
Frank DeAngelis helped students escape harm during the massacre.
He now calls the school "a place of strength".
Many here say he is part of what's made it strong.
After 35 years at the school, the last 18 as principal, DeAngelis says he'll retire next year.
"I have been so blessed to have had such a great run," he says.
DeAngelis was in his office the morning of April 20, 1999 when two students attacked the school with guns and bombs, killing 13 people.
"There's not a day that goes by that I don't think about it," he says.
DeAngelis, a consoling force, vowed to stay at least until the class of 2012 graduated.
The school was remodeled and reopened, but forever changed.
"It'll never get back to normal," DeAngelis says now. "We re-defined what normal is."
DeAngelis helped raise awareness nationwide about warning signs of violence, and crusaded anti-bullying campaigns, starting at his own school.
The departure of DeAngelis will not be easy for his close-knit staff, especially those who were there on Columbine's darkest day.
"Frank's been equal parts, protector, leader and friend," says teacher Jason Webb.
"This is such an emotional day, really grief is the only way to describe it," adds Paula Reed.
Still, with his final year as principal ahead, his thoughts are of the future.
"It's going to be an interesting year and I'm going to savor every moment," he says.
Copyright 2013 Nexstar Broadcasting, Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.