He was admitted for a staph infection around his artificial knee , a problem that almost killed him in 1959 and recurred every five to seven years since .
Butler died at UPMC Shadyside in Pittsburgh on May 11 , 2013 .
Butler was admitted for a staph infection around Butler 's artificial knee , a problem that almost killed him in 1959 and recurred every five to seven years since .
Butler died at UPMC Shadyside in Pittsburgh on May 11 , 2013 .