When it comes to situations like that I tend not to like technical answers.  I believe God's grace and compassion is far greater than we can fathom.  I think these things are a result of mental illness, whether it is depression, bi polar or whatever.  I don’t know what the right thing to do when something like that happens in the community, but I do know that it isn’t good to hide or pretend it never happened.  Folks who were close to them often like to talk and reminisce, I think it helps.