David Letterman, the Late Show With David Letterman staffers and fans are saddened by Antonio Emilio Mendez Jr.’s passing, better known as Tony Mendez, a popular member of the show that became famous thanks to his regular onscreen presence.

The Cuban native worked holding the cue cards besides the camera for Letterman for 21-years. Besides his job as the “cue card boy,” Mendez hosted The Tony Mendez Show for the Late Show website.

According to Deadline, he started handling cue cards for Letterman during the NBC’s Late Night With David Letterman era.

©Late Show With David Letterman

Mendez knew how valuable his job at the show was and how it could affect the person talking to the camera. “The flipping of the cards is very important,” he told The New Yorker in 2001. “If you flip too fast, they can’t see the last line. If you’re too slow, you slow them down.”

Unfortunately, after a 2014 incident involving Mendez and one of the show writers, Bill Scheft, his time with the show ended. As reported by the publication, Mendez physically assaulted Scheft after an argument over a cue card change. Mendez allegedly pushed the writer against a wall while grabbing his shirt.

“He tells me what to do, and I have to say, ‘I know what I’m doing,’” Mendez told The Post about the incident.

After learning about Mendez’s death, Scheft said to The New York Times that “It was an unfortunate way to end his time at the show, and a sad way to end a 22-year friendship.”