Legendary filmmaker Ivan Reitman passed away over the weekend at the age of 75, leaving his family, friends, and fans the world over feeling heartbroken over the loss. Reitman, who directed the original Ghostbusters movie along with its first sequel Ghostbusters II, returned to produce last year's Ghostbusters: Afterlife. The producer's son and the director of the film, Jason Reitman, posted a message to Instagram commenting on the loss of his father."I’ve lost my hero," he writes, posting several family photos. "All I want in the world is the chance to tell my father one more story. He came from a family of survivors and turned his legacy into laughter. Thank you for the many messages of kindness. Please enjoy his movies and remember his storytelling gifts. Nothing would make him happier."

Some of the Ghostbusters cast members have also expressed their grief over Reitman's death. Per Deadline, Dan Aykroyd said in a statement, "Feeling heartbreak today for Geneviève, Catherine, Caroline, Jason and family. The loss of my friend, collaborator, champion and one of the last great creative talents of the BIG SCREEN ERA crumples me. Now on Thursdays who am I gonna call?”

"I am deeply saddened by the loss of Ivan’ Reitman," writes Winston Zeddemore actor Ernie Hudson in a tweet. "Truly a great man and filmmaker who I had honor and privilege of knowing and working with. Deepest condolences to Jason and the entire family. May he RIP."

Ghostbusters: Afterlife's Carrie Coon adds: "Working with Ivan was an honor and a pleasure and I’m so grateful that I was invited into the universe he helped to build, one that continues to resonate with fans the world over."

Paul Feig, the director of Ghostbusters: Answer the Call, also spoke out in honor of Reitman. Feig said on Twitter, "I’m in absolute shock. I had the honor of working so closely with Ivan and it was always such a learning experience. He directed some of my favorite comedies of all time. All of us in comedy owe him so very much. Thank you for everything, Ivan. Truly."

"One of the most special moments to me was after our last test screening of Ghostbusters: ATC after we did some reshoots and our scores went through the roof. Ivan met me out in the lobby and said 'I’m so happy for you I feel like crying.' That’s the kind of generous man he was," Feig said in a follow-up tweet. "Sending so much love to the great Jason Reitman for the loss of his amazing father Ivan. Jason and Ivan have always been so supportive of me throughout my career and I’ll never be able to truly repay them both. This is such a sad day."

Related: Jason Reitman Reveals Father Ivan's Secret Cameo in Ghostbusters: Afterlife

Ivan Reitman Knew the Ghostbusters Theme Song Would Be a Hit

Ray
Ray Parker Jr.

Remembering Ivan Reitman, Ray Parker Jr. spoke with Variety about how the Ghostbusters director was the only one who saw the potential in the film's iconic theme song. Not only that, Reitman was so excited about directing the music video version that even Parker himself questioned what it was that Reitman had seen in it.

"He’s the one who picked the song — everybody else thought it was a little bit crazy," Parker says. "Ivan called me up and said, 'I like what you’re doing with that, can it be longer? Can you make it a record? Can it be something else?' I thought it was good for the film but I was like, 'You wanna make a record out of that?” But he heard it clearly. In the parts I turned in, some were supposed to be background parts, but he wouldn’t even let me re-sing it! He said, “I like the way you’re signing it, the slang and everything” — so we kept the demo because he loved it all."

Parker added, "He thought it was a hit when nobody else did — including myself! So that’s how things turned around, and we got the [longer official] version, and he got so excited about the song that he wanted to direct the video — that’s the only video he ever directed — and there was an [extended] version and it came out on the radio, then they put the album together. So it’s been an unbelievable experience over the last, what is it, 38 years?"

Clearly, Ivan Reitman had meant a lot to so many people, and he will be forever missed. Rest in peace.