LOUISVILLE, Ky. (WDRB) -- An amateur fighter died Saturday after an Mixed Martial Arts fight in Louisville.

Donshay White fought Saturday night at Expo Five on Seventh Street Road during the Hardrock MMA 90 fights. A witness said White was having trouble defending himself but wouldn't submit, so the referee stopped the bout about two minutes and 20 seconds into the second round. White's opponent, Ricky Muse, was declared the winner in his first amateur fight. 

The Kentucky Boxing and Wrestling Commission said White received medical attention on site before being taken to the hospital.

"He looked exhausted," BJ Ferguson, another fighter who witnessed the fight, said of White.

Officials with Bluegrass MMA said White, who was from Radcliff, Kentucky, collapsed backstage after the fight. A doctor and medics were already on scene at Expo Five, but they could not revive him. He was pronounced dead at 9:02 p.m.

"Absolutely the worst possible fear as a promoter of Mixed Martial Arts is somebody would, one, get injured or hurt severely and, two, lose their life," said Gary Thomas with Hardrock MMA. "So every emotion of sadness, fear and remorse just overwhelms you."

The promoter of the fight, Hardrock MMA, is now shifting focus to what went wrong. The Shively Police Department opened a death investigation, and the Jefferson County Coroner's Office has not ruled on a cause. It's pending toxicology and autopsy results, though officials suspect cardiac arrest. 

The Kentucky Boxing and Wrestling Commission is doing its own autopsy, examining policies, procedures and rules for MMA. Last year, the agency overseeing combat sports in Kentucky re-wrote all of its bylaws, adding more medical provisions for amateur fighters. 

"I just hope the sport can continue," Ferguson said. "I don't want to see them try to shut it down because this happened."

White passed two physicals last week, including one an hour before this fight. White's former trainer, Billy Smith, was not in his corner Saturday night, but he said the 37-year-old fighter was not in great shape. Smith believes the fallout from his death will bring more regulation from the state.

"You're going to have to take it seriously, and I think it will bring some new kind of  rules and laws," Smith said. "You are going to have to have a better resume to step in that cage from now on."

A second fighter also received medical attention Saturday night and eventually recovered but at that point, all remaining fights were canceled.

"This was a guy who had goals and had dreams and was fighting for those dreams and died for them," Smith said. "I mean, that's powerful in my mind."

White was only on his second amateur bout Saturday. The first he won in November of 2015. 

Whether professional or amateur, any MMA fighter dying in the cage or right after a fight is unusual. In the United States, it's only happened about five times in the history of the sport.

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