Memorable scenes where someone has an emotional breakdown?

Sarah (Glenn Close) The Big Chill - crying alone in the shower

Travis Walton ( DB Sweeney) under the kitchen table in FIRE IN THE SKY

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already mentioned but among the first that came to mind:

Kathy Bates in AT PLAY IN THE FIELDS OF THE LORD - one of the bravest actors ever !
Robin Williams in THE FISHER KING - shudderingly frightening scene when the red knight appears
Sally Field - STEEL MAGNOLIAS - cemetery scene
Orson Welles Kane wrecking the bedroom