The father of a "cyberbullying" victim has described the moment he found out his daughter had killed herself, and has called for more regulation of social network sites.
Hannah Smith, 14, from Lutterworth, Leicestershire, was found hanged on Friday after being bullied on website ask.fm.
Her sister, Joanne, 16, found her hanged in her bedroom.
The girls' father, David Smith, said he was driving his lorry when Joanne called him to break the news.
"I was 50 miles away in a lorry and I got a phone call from Joanne to say Hannah has hung herself," he told Mirror Online.
"And then Joanne put the phone down on me and I had to ring back to find out what was happening because I didn't have the faintest idea what was happening.
"And then I spoke to my brother and my brother turned round to me and he said 'Hannah's hung herself'. And I said 'Is she dead?' and he said 'Yes' and I just broke down.
"I turned the lorry round as fast as I could to get back."
Ask.fm described Hannah's death as a "true tragedy" and promised to work with police investigating the incident.
The question-and-answer site allows users to send messages to one another without their identity being disclosed.
Although users have to register an email address, name and date of birth, those posting messages can do so anonymously.
A spokeswoman for ask.fm said: "Hannah Smith's death is a true tragedy; we would like to convey our deepest condolences to her family and friends.
"We have reached out to the Leicestershire police and would be happy to co-operate with their investigation into the true circumstances of her suicide.
"Ask.fm actively encourages our users and their parents to report any incidences of bullying, either by using the in-site reporting button, or via our contact page.
"All reports are read by our team of moderators to ensure that genuine concerns are heard and acted upon immediately - and we always remove content reported to us that violates our terms of service."
Mr Smith, 45, found the ask.fm messages the morning after Hannah died.
"There's something not right with the world today if people can tell somebody to die so many times that they actually do it," he said.
"Me, personally, I think ask.fm - the people that run it - should get done for manslaughter or murder because you try contacting them and they just don't care. They don't care that teenagers are dying and killing themselves. It can't be right.
"These websites should be got rid of. If nothing else they need to be regulated."