Kimmel, whose show is on hiatus until next month, Tweeted, "thank you for your kind words about a very kind man - my Uncle Frank - who passed away this morning."
Prior to engaging in hi-jinx with his nephew on the ABC late-night show, Potenza was a Korean War veteran who worked 20 years as a New York City police officer. He also worked for 20 years as a security guard at Caesar's Palace in Las Vegas and at St. Patrick's Cathedral in New York.
In 2003, Kimmel asked Potenza to move to Los Angeles to join his then-upstart talk show as security guard and on-air contributor.
"During his nine-year run on-air, 'Uncle Frank' contributed many great moments to Jimmy Kimmel Live!," the show said in a statement. "He was beloved by his co-workers and considered an Uncle to all. His kindness and humor will be missed by everyone he touched."
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