Almost a full day before police knew about the murder/suicide of celebrity wrestler Chris Benoit and his family, two seperate wikipedia entries were posted about his wife's death. 

Benoit, his wife Nancy and their seven-year-old disabled son Daniel were found dead on Monday afternoon – but the previous day at least two users posted news of Nancy's death on wikipedia.
Information about Benoit on the online encyclopedia was first altered to include news of his wife's deaths by a user in Connecticut, reporting on why the wrestler failed to turn up for a match.
An editor removed it, because of a lack of evidence.
About an hour later another user posted about the death of Benoit's wife, citing several pro wrestling sites.
It was again removed.