Former heavyweight boxing champion Muhammad Ali has died, according to a family spokesperson cited by ABC and NBC.
Ali had been suffering respiratory issues this week and was hospitalized in Arizona, according to sources cited by Reuters.
"It's extraordinarily grave. It's a matter of hours," the source told the newswire service earlier Friday.
Ali, 74, was diagnosed with Parkinson's disease in the 1980s. He was being treated for a respiratory problem that is complicated by the neurological disease, The Associated Press reported.
The news marked a significant apparent downturn for the former boxer. On Thursday, Ali's condition was described as "fair."
Muhammad Ali through the years:
Ali has been hospitalized several times over the years, most recently in early 2015. The Hollywood Reporter noted that he has looked "increasingly frail" in public appearances, "including April 9 when he wore sunglasses and was hunched over" during an event in Phoenix.
Ali's daughter, Laila, who was an undefeated boxer, is reportedly among Ali's nine children with him at the hospital in Arizona. She thanked fans for their support and posted a baby picture of her daughter, Sydney, who was born in 2011, being held by the boxing legend.
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