Jimmy Kimmel's uncle Frank Potenza, aka Uncle Frank from the ABC late-night talk show "Jimmy Kimmel Live!," died at age 77 on Tuesday, August 23.
"Thank you for your kind words about a very kind man - my Uncle Frank - who passed away this morning," Kimmel said about his real-life uncle on his Twitter page in response to a flood of Tweets from fans.
The cause of Potenza's death was not made public.
The New York native and Korean War veteran worked as a police officer for 20 years and was also a private security guard at Caesar's Palace in Las Vegas and at St. Patrick's Cathedral in New York before he began his entertainment career.
"Jimmy Kimmel Live!" debuted in 2003 and Potenza had moved to Los Angeles to work with Kimmel, who was at the time known for his previous series, "The Man Show."
Potenza began appearing on "Jimmy Kimmel Live!" regularly around 2006 and often starred in skits and promotional segments with Guillermo Rodriguez, who once worked solely as a security guard in the parking lot of the show's studio.
Potenza often donned a security uniform on "Jimmy Kimmel Live!" and last appeared on the talk show in June. The program is on hiatus until September 6. Potenza often welcomed members of the show's studio audience in person and was touted for his sense of humor and cheerful demeanor on and off-camera.
"He was one of a kind," Tweeted Don Barris, a friend of Potenza and Kimmel and a comedian who warms up the audience of "Jimmy Kimmel Live!" before tapings. "I already miss him!"
Potenza is survived by three daughters and a newborn granddaughter. His other nephew and "Jimmy Kimmel Live!" writer, Kimmel's cousin Sal Iacono, Tweeted: "I will miss my Uncle Frank dearly. A great man, friend, comedian." He also posted a clip of a "Jimmey Kimmel Live!" skit featuring Potenza and his then-wife, Conchetta "Chippy" Potenza.
Check out several skits featuring Frank Potenza, aka Uncle Frank, on "Jimmy Kimmel Live!" below.