I think we need to be aware of the difference between a suicide /threat/ ("I am going to/I want to kill myself") and a suicide /note/ ("By the time you read this, I will be dead"). I see no other legitimate course of action in the latter case than contacting the local police immediately.
****** I disagree. If we embark on the slippery slope of parsing these notes and attempting to intuit their sincerity then we head into trouble. Maybe not this time or the next instance, but eventually. In a worst case scenario some editor who is sincerely and passionately *wrong* upbraids a genuinely suicidal adolescent, who shortly afterward jumps out a window and becomes a quadriplegic.
These situations are beyond Wikipedia's scope, period. Hand them over to the professionals who have training and experience and access to social services.
-Durova