'The Simpsons' Pays Heartfelt Tribute To Late Mrs. Krabappel Actress On Sunday's Episode

Sunday's episode of "The Simpsons" paid tribute to the late Marcia Wallace in the series' opening sequence.

Every episode usually opens with Bart writing a different message on a classroom chalkboard starting "I will not …" over and over again as a form of punishment.

During Sunday's episode, one single sentence was seen on the familiar board: "We'll really miss you Mrs. K."

Late last week, Wallace passed away from breast cancer. She voiced fourth-grade teacher Mrs. Edna Krabappel for 23 years.

Series executive producer Al Jean said in a statement the show will retire the character as a result of Wallace's passing.