Rance Howard has died aged 89 years old.

The late actor has sadly passed away, and the tragic news was confirmed on social media on Saturday (25.11.17) by his 63-year-old son Ron, although the cause of death remains unknown.

The 'Happy Days' star - who also has a 58-year-old brother Clint - tweeted: '' Clint & I have been blessed to be Rance Howard's sons. Today he passed at 89. (sic).''

In the post Ron continued to praise his parent for his ''personal integrity'' and ''ambition''.

He added: ''He stood especially tall 4 his ability to balance ambition w/great personal integrity. (sic).''

And the filmmaker has hailed the 'Apollo 13' star for ''changing the course of [their] family history'' through his love of acting, which has encouraged the Howard family to follow in his footsteps and enjoy successful careers in the entertainment business also.

Ron concluded: ''A depression-era farm boy, his passion for acting changed the course of our family history. We love & miss U Dad (sic).''

And just moments after hearing the news heartfelt tributes have come flooding in, including sweet messages from his relatives and fellow actors Russell Crowe and Josh Gad.

Rance's - whose real name was Harold Engle Beckenholdt - granddaughter Bryce Dallas Howard has also taken to social media to remember her late grandparent.

The flame-haired beauty shared an image of Rance's ''favourite poem'' titled 'Gone From Our Sight' on the mico-blogging site, which she vowed to recite in his memory.

She captioned the upload: ''My grandfather, the patriarch of our family's favorite poem, he could recite it from heart. I think I'll do the same now. (sic).''

And the 'A Beautiful Mind' star - who appeared in the movie created by Ron - also shared his condolences on Twitter.

He wrote: '': ''Hey @RealRonHoward my deepest condolences.

''He was a fine man indeed was Rance Howard. Fine man, fine actor.

''Being in his company was always a pleasure. (sic).''

Josh Gad has also spoken out about the loss, in which he hailed Rance - who was previously married to Jean Speegle Howard for over 50 years before she passed away, and later wed Judy Howard in 2001 - a ''personal friend'' and ''legend'', who welcomed the 'Beauty and the Beast' actor when he first arrived in Los Angeles.

The 36-year-old tweeted: ''Today we lost one of the greats: #RanceHoward, who I was proud to call a personal friend. When I first arrived in LA , he opened his home to me & made me feel like family. He was a legend, both as a person & performer. @BryceDHoward & @RealRonHoward sending lots of love. (sic).''