Anne Marie Hochhalter, who was partially paralyzed in the Columbine High School shooting but found the strength to forgive the mother of one of the shooters, has died.

Anne Marie Hochhalter, who spoke publicly about the long-lasting effects of gun violence after she was paralyzed in the 1999 mass shooting at Columbine High School in Colorado, was found dead on Sunday at her home in Westminster, Colo. She was 43.

Hochhalter suffered devastating injuries. She told PEOPLE in 2004 that she had just stepped outside for fresh air when she heard a popping noise and suddenly felt something strike her back, which she initially believed was a paintball. As a friend helped her, she was struck again by a bullet, which this time hit a vein.