Bob D'amico / ABC
There won't be much laughter tonight.
"It is with great sadness that the staff and crew of 'Jimmy Kimmel Live!' mourn the loss of 'Uncle Frank' Potenza," ABC said in a statement.
"Thank you for your kind words about a very kind man -- my Uncle Frank -- who passed away this morning," the late-night host tweeted.
Potenza, 77, was a security guard for the show, and made appearances numerous appearances during his nine years on the program, including in segments called "Guillermo's Hollywood Round-Up" and "Uncle Frank and Aunt Chippy's Adventures." Prior to working on his nephew's late-night program, Potenza was a New York City police officer, and security guard at Caesar's Palace in Las Vegas.
"He was beloved by his co-workers and considered an uncle to all," the network said. "His kindness and humor will be missed by everyone he touched."
Which was your favorite bit featuring Uncle Frank? Tell us on our Facebook page.
More in The Clicker: