"Fell apart" doesn't really connote laughing anymore. I'm not sure it ever did, really.
What about "Meredith Lane," played by Sheila Smith in the original? Right before "Who's That Woman," she utters her one and only line in the show: "This number winded me when I was nineteen."
Sheila was the standby for Alexis Smoth, Yvonne De Carlo and Fifi D'Orsay. After standing by for Angela Lansbury in mame, she went on to achieve the rare distinction of playing both Mame and Vera on Broadway:
Here she is, 38 years after Follies (42 yars after that photo), playing Madame Armfeldt in a Westchester production of A Little night Music: