In the video titled 'Too Late', teenagers read out real messages left on the social media accounts of bullied children.
"You are beautiful and unique in every way" reads one teenager.
Another says, "I want to thank you for all the times you were there for me, and for being the greatest friend anyone could ever ask for."
The viewer then learns that these heartfelt messages were sent to teenagers who are no longer with us, having died by suicide.
The next message read out says: "Everyone misses you, I just wish you were here to see it. I love you."
The heartbreaking video ends with the words 'Be Nice. Now.' A message from American charity Champions Against Bullying, which commissioned advertising agency Deutsch NY to produce the video.
Story continues below the video
Almost all children will experience or witness bullying while at school, according to a national survey by Bullying UK published in November 2014. 93;display:block;}