That's the normalization of deviation in the real world at work. Less than a few weeks ago a suicide bomber blew up half a city block and it's already been forgotten because there is so much other crap happening.
That suicide bombing was really strange. It seems the person might have deliberately chosen a time when there would be no one around and made sure to warn anyone who might be in the area to get away before detonating the bomb. This would seem to indicate the person did not intend to commit mass murder, only property damage.