LITTLETON, Colo. (AP) – Red roses placed on 13 black granite crosses Wednesday honored those killed at Columbine High School six years ago in the nation’s deadliest school shooting.

No formal observances were planned in the memory of the 12 students and one teacher who were gunned down in 1999 by students Eric Harris and Dylan Klebold at the suburban Denver high school. The two teens then shot and killed themselves.

Friends and family members of the victims stopped at the cemetery memorial with flowers, pausing among the more than 5-foot-tall crosses and the 13 memorial trees blossoming with white flowers.

Cindy Thirouin, whose stepfather died that day, brought red roses for each cross.

She and her two children came to celebrate his life, not to mourn, she said.

“After six years, it’s getting easier, and it’s time to move on,” she said.

Columbine teachers gathered at the school Wednesday for a quiet remembrance. The campus was closed to outsiders and students were given the day off. Teachers reported for an in-service day.

They planned a moment of silence in memory of the victims. Principal Frank DeAngelis, who was principal then, planned to read the names of the victims over the public address system.

Of the roughly 140 teachers and staff who taught at Columbine at the time of the shootings, about 30 remain.

“It’s difficult because it is a reminder,” said Jefferson County schools spokesman Rick Kaufman of the anniversary. “Canceling classes is an opportunity for us to remember the victims – not necessarily the tragedy, but those 13 that died. It’s a reflection back but we’re also looking forward.”

About $700,000 has been raised for a memorial to honor the victims, but fundraising has stalled as the local economy slowed and other tragedies occurred, including the Sept. 11 terrorist attacks, organizers said.