Cass Warner, the author-filmmaker granddaughter of Warner Bros. co-founder Harry Warner, died at the age of 76. Her son Cole Hauser, who acted in Yellowstone, announced the news of Cass' death on Instagram.  “Her kindness, love, humor and amazing spirit will be missed by not only my family but the world. You have touched so many,” Cole wrote.

The eldest of the four Warner brothers and Cass' grandfather, Harry founded the eponymous studio with his siblings Sam, Jack, and Albert in 1923. Then, Cass was born to Betty Warner and Milton Sperling on March 8, 1948. Years later, she sat with her producer father Milton as he discussed stories with aspiring filmmakers. Then, filmmaker Howard Koch of Warner Bros. classics like The Sea Hawk, The Letter, Sergeant York, and Casablanca mentored Cass.

Her films include documentaries such as The Brothers Warner, based on her book 'Hollywood Be Thy Name: The Warner Brothers Story', and Hopper: In His Own Words. The Brothers Warner also came as a segment of the series American Masters on PBS.

She is survived by her grandchildren, Colt, Steely Rose, and Ryland.