Boxing’s “greatest of all time” is being remembered by celebrity fans and friends. He was 74.

The three-time heavyweight champion died at the Phoenix-area hospital he had spent the past few days being treated for respiratory complications.

Hollywood A-listers and sports stars expressed their condolences on social media with many of them posting well-known photos of the sports hero.

“RIP @muhammadali, a legend who transcended sport and was a true champion for all. #thegreatest #MuhammadAli,” tweeted retired boxer Oscar De La Hoya.

“God came for his champion. So long great one. @MuhammadAli #TheGreatest #RIP,” said Mike Tyson.

“Goodbye champ. Fly like a butterfly….” Josh Gad wrote on Instagram.

“Muhammad Ali is dead at 74! A truly great champion and a wonderful guy. He will be missed by all!” Donald Trump tweeted.

“Yes you did Mr Ali. You shook up the world Sending love and light to the family #RIP,” Kate Hudson captioned a video of some highlights from Ali’s career.

One day before Ali’s death, boxer Manny Pacquiao tweeted: “Please keep @MuhammadAli in your thoughts and prayers. With God, all things are possible.”

This article originally appeared on People.com

For much more on Muhammad Ali, see TIME’s ALI: The Greatest, a 112-page, fully illustrated commemorative edition. Available at retailers and at AMAZON.COM

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