I don't know about that; I think Quiet Dom not saving his son from death may be more disturbing to me. But yea, A brother murdering another brother is horrid.
Let's also not forget, Steve Maggaddino kidnapping his cousin Joe Bonanno. It's been said that this was a faked kidnapping, however.
“I called your f—— house five times yesterday, now, if you’re going to disregard my m—– f—— phone calls, I’ll blow you and that f —— house up… This is not a f—— game. My time is valuable. If I ever hear anybody else calls you and you respond within five days, I’ll f—— kill you.†~ John Gotti.