Hollywood has lost a beloved icon, Richard Simmons.

The fitness legend, who remained out of the spotlight in recent years, died July 13, one day after his 76th birthday.

According to NBC News, citing two law enforcement sources familiar with the situation, Simmons was found unresponsive Saturday morning at his Hollywood Hills home.

After receiving a call around 10 a.m. local time, the outlet reported, LA Fire and LADP arrived at the house and Simmons was pronounced dead at the scene. His exact cause of death is pending.

On July 12, one day prior to his death, Simmons reflected on his past birthday celebrations.

"When I taught class at Slimmons," he wrote on Facebook, referencing his former studio, "they would have special cakes made for me."

"One was a sheet cake airbrushed with my picture on it…….one was a Barbie doll and her dress was the cake," he continued. "Also what about that cake with a big Disco ball on top. It was my birthday when we taped Groovin in the House . …that one was a three dimensional three foot cake in the shape of one of my Dalmatians … You know I cried."

Simmons went on to send his fans a message of gratitude.

"So many of you have sent me birthday wishes on my Facebook and other platforms," he shared. "I really appreciate that. I don’t know when your birthday is but I wish you a happy and healthy birthday!"

Later in the day, Simmons returned to his Facebook page to acknowledge, "I never got so many messages about my birthday in my life! I am sitting here writing emails. Have a most beautiful rest of your Friday."

Early July 13, one final message was sent from Simmons' account.

Keep reading to revisit Simmons' life in photos...

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