Owner of the legendary Kronk Gym and one of boxing's greatest trainers, Emanuel Steward, is dead at age 68.

According to Steward's assistant, Victoria Kirton, the trainer died Thursday in a Chicago hospital, the Huffington Post reported.

Heavyweight champion Wladimir Klitschko, whom Steward trained, also confirmed his death.

"Boxing has suffered a tremendous loss with the passing of Emmanuel Steward," Klitschko said in a statement.

Joseph Donofrio, Palace fight promoter said, "The boxing world has lost one of its most valuable and honorable assets with the loss of Emanuel Steward.

"He was not only my mentor in the world of promotions but also to thousands of others here in Detroit and his extended reach throughout the world."

The Inquisitr confirmed that the trainer was taken to the hospital in September. He went through surgery for diverticulitis, a stomach disorder he suffered from. After that, his health continued to go downhill. A prayer vigil was held in Walled Lake for Steward on Sept. 23.

Steward has left the world of boxing with a mark that will hardly be forgotten. He has trained a number of fighters, guiding Thomas Hearns, Hilmer Kenty, and Milton McCrory to world titles in the 1980s.

"Emanuel was Mr. Boxing in Detroit," Frank Garza, a leading Michigan fight referee and close friend of Steward said. Garza was devastated after he heard the news of his dear friend's death. "He was like Gordie Howe is to Detroit hockey and Al Kaline to Detroit baseball."

The news quickly spread through the boxing world, with many boxing officials, fighters, fans and even television executives, paying their respect to the late trainer.

Steward's legendary Kronk Gym was a place where his fighters were clad in red and gold trunks.

The exact cause of his death is still unknown.