The Simpsons actress Marcia Wallace passes away

US actress Marcia Wallace, best known as the voice of Bart Simpson's teacher Edna Krabappel, has died at the age of 70.

Her death was announced in a statement from executive producer Al Jean.

Wallace won an Emmy in 1992 for her work on The Simpsons, as a jaded, grumpy fourth-grade teacher, forced to put up with Bart's antics.

Jean said her "irreplaceable character" would be retired from the show.

Her character was known for the catchphrase "Do what I mean, not what I say" and exclaiming "Ha!" in disgust.

It is unclear when the actress died or what the cause was.

She had previously survived breast cancer, which she wrote about in her memoir Don't Look Back, We're Not Going that Way, published in 2004.

Harry Shearer, the voice of her on-screen husband Ned Flanders, told the Associated Press that Wallace "brought this huge, positive energy" to her work on The Simpsons.

"She was just a warm and wonderful person," he said.