Sesame Street” is saying farewell to three longtime cast members — Bob McGrath, aka “Bob,” Emilio Delgado (“Luis”) and Roscoe Orman (“Gordon”). McGrath had been part of the show since it premiered in 1969, Delgado made his debut in 1971, and Orman joined the show in 1974.

According to MuppetCast, McGrath broke the news at a recent convention, stating, “As of this season, I have completed my 45th season this year. And the show has gone under a major turnaround, going from an hour to a half hour. HBO has gotten involved also. And they let all of the original cast members go, with the exception of Alan Muraoka — who is probably 20 years younger than the rest of us — and Chris Knowings, who is also young.”

Sesame Workshop denied any interference from HBO in a statement: “Bob McGrath, Emilio Delgado (“Luis”) and Roscoe Orman (“Gordon”) remain a beloved part of the ‘Sesame’ family and continue to represent us at public events. To us, and for millions of people worldwide, they are a treasured part of ‘Sesame Street.’ Since the show began, we are constantly evolving our content and curriculum, and hence, our characters, to meet the educational needs of children. As a result of this, our cast has changed over the years, though you can still expect to see many of them in upcoming productions. As we’ve stated previously, Sesame Workshop retains sole creative control over the show. HBO does not oversee the production.”

PBS CEO Paula Kerger addressed the cast changes during PBS’ Television Critics Association summer press tour on Thursday, since the public broadcaster continues to air new episodes of the beloved children’s show six months after they debut on HBO. “As you know, ‘Sesame Street’ is produced by Sesame Workshop, an independent production company,” she said. “The casting decision was made by them. We did not know about it beforehand. We found out about it after.”