Friends called Sylvie Cachay a "darling" of the fashion world.
"I'm devastated and still in shock," said Kim Figuerola, a business partner and friend of Cachay's. "I do want to make people understand how bright our star was."
Cachay designed for Tommy Hilfiger and Victoria's Secret before breaking out to start her own fashion line of swimsuits.
Photos on her website show her celebrating her own swimwear line called "Syla" at the SoHo House.
Janice Ellinwood, a professor at Marymount University in Virginia, where Cachay studied, described Cachay as a vivacious young woman and a talented designer.
"She had a grace about her," Ellinwood said. "She had humility, and she also took great pride in her work."
Cachay's friends and family released a statement saying that "the world has lost a beautiful soul. She will be deeply and painfully missed."
ABC News' Richard Esposito, WABC-TV in New York and The Associated Press contributed to this report.