Jon Landau, the Oscar-winning producer of Avatar: The Way Of Water and Titanic, has died. Per Variety, Landau died of cancer on Friday. He was 63.

“A great producer and a great human being has left us,” Landau’s longtime artistic collaborator James Cameron said in a statement. “Jon Landau believed in the dream of cinema. He believed that film is the ultimate human art form, and to make films, you have to first be human yourself. He will be remembered as much for his vast generosity of spirit as for the movies himself.”

“Jon was my right hand, and I was his. In recent years, we became a trapeze act… total interdependence, total trust, total synchronization. We became not only the closest working partners, but the closest of friends. My last message to him was not only that I loved him but that I missed our daily dialogue.”

Landau’s work speaks for itself. He began collaborating with Cameron on the set of True Lies, where, the director recalls, Landau was the “studio ‘suit’” assigned to the production. The pair would go on to produce three of the five highest-grossing films ever: Titanic, Avatar, and Avatar: The Way Of Water, each grossing more than a billion dollars, with the first Avatar still sitting atop the global box office charts. As successful as these films were, all three were intense, complicated productions for which Landau appeared more than game.

“When I read something like Titanic, honestly, I don’t even think about the water,” Landau told The A.V. Club last December. “I am so wrapped up in the characters’ story. The water is secondary because I know that we’re going to figure out how to do whatever the production issues are […] When I read something like Way Of Water and [James says], ‘Jon, it’s more water.’ I go, ‘I want more water. Bring more water.’ Because I’m a diver, I love scuba diving and being able to share that experience with other people. I think that’s what Avatar: The Way Of Water does: People feel like they are going on their first dive underwater.”

Born in New York City on July 30, 1960, Landau was the son of movie producers. His parents, Edie and Ely, founded American Film Theater and produced Sydney Lymet’s Long Day’s Journey Into Night and the Martin Luther King Jr. documentary King: A Filmed Record…Montgomery To Memphis, for which Ely received an Oscar nomination.

After attending USC School Of Cinematic Arts, Landau made his name in special effects-driven blockbusters, co-producing 1989’s Honey, I Shrunk The Kids and Dick Tracy. The following year, he was named senior vice president of feature production at 20th Century Fox. As part of Fox’s leadership, Landau oversaw the production of such hits as Home Alone and Speed. Landau didn’t produce for nearly a decade after taking the job but was lured to sea by Cameron and his script for Titanic. Despite many believing the film to face a similar disaster as the ship, Titanic became an international box office sensation, earning Landau an Oscar. Though many live by the cinematic credo “Never bet against James Cameron,” the axiom could be just as easily applied to Landau. They might not be among the highest-grossing features ever, but Landau’s non-Avatar-related output, Alita: Battle Angel, and 2002’s Solaris, continue to linger as cult classics.

Landau was also the COO of Lightstorm Entertainment, the production company Cameron and Lawrence Kasdan founded. Landau was in charge of the many ancillary projects from Cameron’s epics, including Avatar spin-off books, comics, video games, and the Pandora Park at Disney World. Before his death, he was deep in the production of the upcoming three Avatar movies, the first of which will be released in 2025.

Landau is survived by his wife, Julie, and sons, Jamie and Jodie.