By Ben Warwick

LITTLETON, Colo. (CBS4) – Saturday marks 20 years since the Columbine High School shooting. There are several remembrance ceremonies planned to honor the victims and survivors of the tragedy.

Two gunmen killed 12 students and a teacher on April 20, 1999.

(credit: CBS)

On Thursday, the community will gather at Waterstone Community Church at 6:30 p.m. for a non-denominational, faith-based remembrance service. Families, survivors, and community members will speak at the service. Speakers include former Columbine High School principal Frank DeAngelis, Patrick Ireland, Columbine principal Scott Christy, Crystal Woodman-Miller, Philip Yancey, and artist Makoto Fujumura. RSVP is required and a $20 donation from each attendee will go to future maintenance and upkeep of the Columbine Memorial.

On Friday, a community vigil is scheduled for 7:30 p.m. at Clement Park in Littleton.

(credit: CBS)

On Saturday, the Columbine Memorial Foundation will host a remembrance ceremony at Clement Park at 3 p.m. for the community. Also Saturday, current Columbine students will spend the anniversary volunteering for private service projects around the neighborhood to give back to the community.

Ben Warwick