Marcia Wallace Dead: 'Simpsons' Actress Dies At 70

Marcia Wallace, best known for her role on "The Simpsons," has died. She was 70.

Wallace voiced Edna Krabappel on the long-running Fox series. Her other roles included stints on "The Bob Newhart Show" and "Murphy Brown."

"I was tremendously saddened to learn this morning of the passing of the brilliant and gracious Marcia Wallace. She was beloved by all at The Simpsons and we intend to retire her irreplaceable character," Simpsons executive producer Al Jean said in a statement, according to The Hollywood Reporter.

Wallace had been battling breast cancer for almost 30 years.

UPDATE Wallace's son confirmed to the LA Times that she died of complications due to pneumonia and was "considered clear" of breast cancer. She had been an advocate for breast health issues for decades. October happens to be Breast Cancer Awareness Month.

Clarification: Language has been amended to reflect that Wallace's age at the time of her death was 70, one week shy of her 71st birthday.