Actually Kanye was singing on stage and a stage hand whispered in his ear. He immediately stopped "Sorry, there is a family emergency" and immediately left the stage.
http://perezhilton.com/2016-10-02-kim-kardashian-kardashians-still-famous-php-perez-hilton-podcast#.V_ISyvArI7Y
Their only real link to celebrity is that their father, Robert Kardashian, was O.J. Simpson's lawyer. Other than that people are just fascinated by their rich lifestyle. Okay, maybe...