Maybe he was depressed. Maybe he was being treated for depression, as some of the drugs they use seem to have suicidal side effects. Whichever way, he wasn't in his right mind, so people should not be too harsh of his actions.
As for where it was done, the place is usually chosen as a way of them blaming whoever should find them - an ultimate "See. look what you drove me to."
The one I am least worried about is his daughter. Youngsters are more resilient than we give them credit for, so she should bounce back from it. For the rest of you, support each other and the hurt will gradually abate, though you will never forget.