Each morning for the last two decades, Frank DeAngelis has recited aloud the names of the 13 people killed at Columbine High School, where he served as principal during the 1999 massacre that marked a modern era of mass school shootings.
On 20 April 999, two heavily armed Columbine students stormed the school in suburban Denver, killing 12 classmates and a teacher before turning their guns on themselves and committing suicide. At the time, it was the deadliest school shooting in US history. "I saw a gunman coming towards me and everything was in slow motion," he said. "But I so vividly remember the sounds of the gunshots breaking the glass behind me."
The mother of a girl left paralysed from the shooting took her own life in public six months after the massacre. He sought professional help to deal with his feelings of grief, sorrow and guilt, and relied on his Catholic faith to give him strength to share his experiences with other schools and communities that have endured mass shootings, from Virginia Tech and Sandy Hook to the 2018 Marjory Stoneman Douglas High School massacre in Parkland, Florida.