Marcia Wallace, whose four-decade television career included playing the secretary on “The Bob Newhart Show” and Bart’s fourth-grade teacher Edna Krabappel on “The Simpsons,” has died, her agent said Saturday. Wallace passed away at age 70 on Friday, October 25, 2013 due to complications from breast cancer.

Wallace starred for six seasons as Carol Kester on “The Bob Newhart Show” in the 1970s and reprised the role in the 1990s on “Murphy Brown.”

But it was her role as Edna Krabappel, Bart Simpson’s teacher, that may have earned her the most fame in recent years. It was a part she held since the show’s premiere in 1990. Wallace won an Emmy for Outstanding Voice-Over Performance in 1992.

Staff of “The Simpsons” had been aware of her recent health struggles. Producer Al Jean said, “I was tremendously saddened to learn this morning of the passing of the brilliant and gracious Marcia Wallace.”