Richard Simmons died at 76 years old. Police reportedly responded to a call from his housekeeper before 10 a.m.

PST on Saturday. He was pronounced dead at the scene with no foul play expected at this time. His cause of death has not yet been revealed, but police currently believe it was natural causes.

A representative for Richard confirmed his death to ABC News . The Mirror contacted the Los Angeles Police Department for comment. The fitness guru celebrated his birthday on Friday, thanking fans for their kind messages and signs of support.

In fact, the star tweeted just hours before his reported death, writing: "Thank you...

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. Love, Richard.

" For all the latest on news, politics, sports, and showbiz from the USA, go to The Mirror US . READ MORE: Richard Simmons YouTube workout clips shared 6 years after he was last seen in public Before his death, Richard reflected on his life, including sharing a story about his first birthday. He shared a picture of him as a child and explained that his mother never baked their cakes, but rather purchased them from different bakeries.

Richard also explained that it was his birthday when they filmed Groovin in the House. He said: "That one was a three dimensional three foot cake in the shape of one of my Dalmatians ..

. You know I cried. So many of you have sent me birthday wishes on my Facebook and other platf.