This home was owned by the victims; it was not a rental.  A tragic event like this does, however, serve to remind everyone that the systems we rely upon every day to live, also need to be respected.  There is not always someone to blame.  Could this have been prevented with CO detectors? Maybe.  We may never know. I can think of two circumstances where a CO detector in my house had alerted either myself or my family to danger.  Either of those times could have ended up as a similar event, or worse.  Please make sure that all of your detectors work, rent or own.  My condolences to the family.