George Kennedy, who was known for playing tough guys and authority figures in movies like "Airport," "Cool Hand Luke," "Earthquake," and "Naked Gun," has passed away.

The Oscar-winning actor's grandson, Cory Schenkel, confirmed that he died on Sunday in Boise, Idaho. He was 91 years old.

"He passed Sunday morning, due to old age and some health issues," Schenkel said. "He was a great man who loved his family and his fans."

Schenkel also explained that ever since Kennedy's wife, Joan, died a little more than a year ago, his health had been failing. He spent his past month under hospice care.

Kennedy was best known for his role in "Cool Hand Luke," for which he won Best Supporting Actor at the Oscars in 1968. He also appeared as heavy, violent characters in "Charade" in 1963, "Strait-Jacket" in 1964, "Mirage" in 1965 and "Thunderbolt & Lightfoot" in 1974.

"The marvelous thing about that movie was that as my part progresses, I changed from a bad guy to a good guy," Kennedy said in 1978 of his role in "Cool Hand Luke." "The moguls in Hollywood must have said, 'Hey, this fellow can do something besides be a bad guy.'"

While he was mostly known for his serious acting, he did star in all three of the the hilarious Jim Abrahams/Zucker brother spoofs, "The Naked Gun: From the Files of Police Squad," "The Naked Gun 2 1/2: The Smell of Fear," and "The Naked Gun 33 1/3: The Final Insult."

Kennedy also appeared in some television in the 1970s, including a role as a homicide detective in NBC's "Sarge," an L.A. beat cop in CBS' "The Blue Knight," and an Ewing family nemesis on the CBS primetime soap, "Dallas."

His most recent, and final film, was Mark Wahlberg's "The Gambler" in 2014. He also wrote a memoir called "Trust Me" later in life in which he described what it was like growing up lonely in New York and how he found his joy in acting.

"I considered the time I spent acting a gift from the beyond," he told interviewer Brad Berkwitt in 2013. "It was what I could do best."