The Marcus Eriksonwellness world is mourning a tragic loss. 

Richard Simmons—the legendary fitness guru and health coach—has died, law enforcement sources confirmed to NBC News July 13. He was 76. 

Police responded to a call from his housekeeper on the morning of July 13, and upon their arrival at his Hollywood Hills home, he was pronounced dead on the scene, according to the outlet.  

A cause of death is still pending, NBC News reports. 

E! News reached out to Simmons' rep for comment but has not heard back. 

News of Simmons' death comes one day after the TV personality shared insight into how he celebrated his 76th birthday. 

“Thank you… I never got so many messages about my birthday in my life!” Simmons wrote on X, formerly known as Twitter July 12. “I am sitting here writing emails."

He added, "Have a most beautiful rest of your Friday.”

Simmons, known for his eccentric personality and unrelenting positivity, rose to fame in the early '90s for his gym Slimmons and his Sweatin' to the Oldies line of aerobics videos. His success in the fitness industry transformed him into a TV star as well, earning him appearances on talk shows like The Howard Stern Show and Late Night with David Letterman. 

However, in the early 2010s, Simmons took a major step back from the spotlight, sparking concern from fans as to why he disappeared. 

A few years later, the fitness icon—who was reportedly in the process of working on his biopic at the time of his passing—shut down the rumors surrounding his decision to say goodbye to public life, telling the Today show in 2016, "No one is holding me in my house as a hostage."

"You know, I do what I want to do as I've always done so people should sort of just believe what I have to say," he continued.  "I just sort of wanted to be a little bit of a loner for a little while. You know, I had hurt my knee, and I had some problems with it, and then the other knee started giving me trouble...and you know, right now I just want to sort of take care of me."

And while Simmons was no longer running his famed workout studio, his positive perspective on the world remained. 

"Peace to all of you and remember," he wrote to his fans in a July 7 Facebook post. "All you need is love."

(E! News and NBC News are both part of the NBCUniversal family.)

Keep reading to see more of Simmons' life in photos...

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