Top trainer and former amateur boxer Emanuel Steward, who worked with several world champions at his fabled Kronk Gym in Detroit and was also a respected television commentator, died in a Chicago hospital aged 68.“He has passed - he’s gone home,” Steward’s sister Diane Steward-Jones told the Detroit Free Press by phone. “He was in no pain, and we sang to him, as well as did the doctors present. He had loved ones around him.”Steward’s girlfriend Anita Ruiz, who is also executive director of the Kronk Gym Foundation, told Reuters the trainer had died after having “complications through surgery” for diverticulitis.Steward ended his amateur career with a record of 94 wins and three losses but is best known as the trainer who transformed Thomas Hearns from a light-hitting boxer into a devastating puncher.Under Steward’s guidance, ‘Hitman’ Hearns became a four-division welterweight champion in the 1980s as he vied with fellow boxing greats such as Sugar Ray Leonard, Roberto Duran and Marvin Hagler.Most recently, Steward trained heavyweight world champion Wladimir Klitschko before he was forced to step aside because of an undisclosed illness.“It is not often that a person in any line of work gets a chance to work with a legend, well I was privileged enough to work with one for almost a decade,” Ukrainian Klitschko said in a statement.“I will miss our time together. The long talks about boxing, the world, and life itself. Most of all I will miss our friendship.“My team and I will carry on with the goals we had set while Emanuel was with us because that is exactly what Emanuel would have wanted ... we will accomplish these goals in his honour.”West Virginia native Steward was central to the famous Kronk Gym in Detroit where he helped shape the careers of fighters such as Hilmer Kenty and Milton McCrory. Later he worked with British and Canadian world heavyweight champion Lennox Lewis.An inductee of the International Boxing Hall of Fame and the World Boxing Hall of Fame, Steward also worked for many years as part of HBO’s commentary team on fights.