"I hoped it would never happen again, but here we are 19 years later, and it has happened again and again and again," Garrigan said in an interview. "But for the first time, I feel hope because these students are using a voice I didn't know I had two decades ago."
Garrigan, mother of a 3-year-old and pregnant with her second child, joined Everytown for Gun Safety's network of gun-violence survivors last year. Everytown was founded by Michael Bloomberg, the former New York mayor. Garrigan said it was the first time she had spoken about her experience with other survivors of similar trauma.
In her speech Friday, she cautioned the assembled students that victims of school shootings carry wounds the rest of their lives.
Her former classmates suffer from survivors' guilt, post-traumatic stress disorder, substance abuse, suicidal thoughts and more.
"This epidemic should have stopped with us," she said.
She later said she likes to remind young survivors to "be nice to yourself" because "you've been through a lot, and you don't always know how that will affect you."
On her shirt, a small metal pin in the shape of a ribbon bore the words, "Never forgotten."