I doubt that the aluminum frame S&W revolver fails "catastrophically" when the classic under-barrel crack appears. While I have never had a K frame crack, I had a 20 year old J frame crack sometime during a 100 round range outting. The odds are 99-to-1 that it cracked sometime before I fired the last round but it was working fine. I found the crack while cleaning it the next day.
We read about a fair number of the J frames cracking but not about one ever coming apart during the shoot that likely broke it. The K frames are doubtlessly the same.