Why? Sure comedy is great in three's (a priest, a nun, & a rabbi walk into a bar), religion is filled with sets of threes (son, father, holy spirit), triangles are the strongest formation. Why does death come in threes? With the recent celebrity passings (Art Bell, R. Lee 'Gunny" Ermey, Barbara Bush among others) It's been kinda difficult to find where one group of 3 ended, and a 2nd, possibly 3rd group have started. With other celebrities of note, Basket Ball Legend Hal Greer, Harry Anderson of TV's Night Court and many more taking steps into the next world, it always seems like it happens in 3's. My mother who worked as a nurse in numerous nursing homes in the Yakima Valley, first told me about the "3" even with her patients. When one would pass, 2 more would follow with in a week and half.

Could it be because of human psychology? Wikipedia calls it "Confirmation bias" or "Myside bias." It is the tendency to search for, interpret, favor, and recall information in a way that confirms one's beliefs or hypotheses, while giving disproportionately less consideration to alternative possibilities. That's why we can see faces in objects and fluffy bunnies in clouds. Maybe that's why we see death in three's. Oh heck, it could be as simple as the fact that 4 is too many, and 2 is not enough. One day I'm sure we'll all find out, then 2 more people will shortly after.