Paulie Gulino, Bonnano associate, was killed because he pushed Anthony Spero (there were probably other reasons)

Larry Carozza, Colombo associate, got killed because he had an affair with Sonny Franzese's daughter, who was married.

Sammy Gravano implied that Louis Milito got killed because he badmouthed his capo Lou Vallario. There were other reasons.

Louis Di Bono got killed because he didn't show up to a meeting scheduled with John Gotti.

Johnny Petrucelli, Lucchese soldier, got killed because he was hiding Gus Farace in his house and didn't obey Amuso's order to kill Farace.