New York Fashion Week was buzzing Thursday not so much about what happened on the runway but what occurred next to it on the front row the day before.

Zelda Kaplan, a celebrated Manhattan socialite and women’s rights activist,  collapsed Wednesday as super models, donning designer Joanna Mastroianni’s latest creations, walked the runway at Lincoln Center.

One witness told the New York Daily News that Kaplan’s eyelids “started to flutter” as the show was getting under way, and then she was out. Another attendee said she thought Kaplan, who had just had her photo taken in a striking red and black dress with matching hat, had just fainted. “She flopped over in my lap,” Ruth Finley, publisher of The Fashion Calendar, told The New York Times.

Kaplan was carried from the runway but couldn’t be revived. She was later pronounced dead at St. Luke’s-Roosevelt Hospital Center.

A regular at night clubs and social events, Kaplan was known for being in the company of the rich and famous. On its website, New York magazine carried a picture of the "beloved party animal" posing with rapper Snoop Dogg at Capitale on the Bowery.