Isiah Whitlock Jr., The Wire Star, Dead at 71

Whitlock, born Sept. 13, 1954, began his acting career in college during Southwest Minnesota State University's production of Arthur Miller's The Crucible, which was "proverbially shot out of a cannon," according to his website's biography.

After making his onscreen debut with a minor role in 1981's A Christmas Carol, the Indiana native took on small parts in several TV shows, including Cagney & Lacey and films like 1990's Gremlins 2: The New Batch and Goodfellas. However, it was his role as Senator R. Clayton "Clay" Davis on The Wire that solidified his spot in pop culture.

In fact, Whitlock became known for his catchphrase "sheeeee-it," an elongated pronunciation of "s--t," which was popularized on the crime drama. Although he first said it in 2004's She Hate Me, Senator Davis began saying the line.

"When I started working on The Wire, I started slipping it in my dialogue," he revealed to the Baltimore Media Blog in 2015. "The writers eventually started writing it in."

And as the series took off, his catchphrase did too.

"It can be up to ten times a day," he explained of how often fans would yell it back to him. "I don't think it's ever going to go away. It took a little while to get used to it. But I'm immune to it now. It doesn't freak me out anymore. It makes everybody happy.

Although the HBO series concluded in 2008, the actor had always looked back at that time with fondness.

"I always looked forward coming to work," he recalled. "The show was so good. They ran a tight ship. Fantastic writing. I had a rare moment of truly enjoying what I was doing. They gave me a lot of freedom to create a character. Flex my muscles so to speak."

For the latest breaking news updates, click here to download the E! News App