Marcia Wallace, who provided the voice of Bart Simpson's teacher, Edna Krabapple, on Fox's "The Simpsons", passed away one week before her 70th birthday.

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

Wallace had been battling breast cancer for 30 years, although sources say that she died from an unrelated illness.