13 people dead, reasons as yet not fully known. Their deaths should be mourned by all, are mourned by all here as far as I can see, and are mourned as deeply as the victims of any other mass killing anywhere.
The greatest tragedy in this mass killing is that one of the victims survived the Las Vegas massacre, only to die in this one.
We need to do something about guns. We need to do something, as well, about whatever the hell has gone wrong in the minds of a hell of a lot of people.