The boss of Pinterest has told the BBC the death of Molly Russell is a daily reminder of the urgent need to make social media safer for young people.
The app - which functions like a digital notice board - hit the headlines when the 14-year-old, from Harrow, in northwest London, took her own life in 2017 after viewing self-harm content online on sites including Pinterest.
A coroner later ruled the material she was exposed to contributed "in a more than minimal way" to her death.
Addressing the case publicly for the first time, Bill Ready - who became Pinterest's boss in 2022 - said he thought about her "every day" and learning the lessons of her death "guides our work".
"As a parent of a young daughter, I can't imagine the pain Molly's family feels," he told the BBC.
