Muhammad Ali dies at 74 after reports of 'grave condition'

Muhammad Ali died Friday evening at a Phoenix-area hospital, a family spokesperson told NBC News. He was 74. 

Earlier in the day reports surfaced that he was in "very, very grave" condition after being hospitalized earlier this week with a respiratory issue. 

"After a 32-year battle with Parkinson's disease, Muhammad Ali has passed away," family spokesperson Bob Gunnell told NBC News.

The boxing legend and American cultural icon's status sent ripples across the sports world Friday afternoon, with fans, media members and fellow athletes alike expressing worry, and later condolences. 

Ali's respiratory problems are complicated by Parkinson's disease, which doctors diagnosed him with in the 1980s, according to Associated Press sources. The disease has visibly weakened him for more than 20 years. 

Ali was hospitalized in the Phoenix area Thursday.

Lance Pugmire of the Los Angeles Times reported Friday afternoon that family members had gathered at Ali's bedside, so serious was his condition. NBC News also reported Ali was in "grave condition" with family members at his bedside. 

Media members, fans and fellow athletes all poured forth condolences and concerns for Ali as reports spread Friday that his condition was potentially life-threatening. A spokesperson for Ali's daughter, Laila, said she appreciates the well wishes, according to NBC News. 

"Laila's number one priority is her father's well-being. She truly appreciates the outpouring of love for her family, as she spends quality time with her dad," the representative said.

This is a developing story ...