For those of you who don't know, Kate Spade was earlier a journalist.
Associated Press also reported that Kate's husband, Andy, was in the apartment at the time. "Holding Kate's family, friends and loved ones in my heart", Ms Clinton tweeted. They asked for privacy during "this very hard time".
After majoring in journalism at Arizona State University, she moved to NY and took a job with the now-defunct Mademoiselle magazine. Spade and her husband Andy cashed out of her name-sake business more than a decade ago.
Her bright and colourfully-patterned designs became a trademark for her brand, which is recognisable for having the spades playing cards symbol logo.
TMZ reports Kate Spade was found dead Tuesday in her NYC apartment by her housekeeper, who found her tied to a closet doorknob with a red scarf. The officials were not authorized to divulge details of the investigation and spoke to the media on condition of anonymity. She changed her name to Katherine Noel Frances Valentine Brosnahan Spade, she said in an NPR interview this year. Spade got her start working in the accessories department of Mademoiselle magazine in Manhattan.
The company was acquired by Neiman Marcus for $125 million in 2007 and Kate and Andy stepped away from day-to-day operations. Years later, after the birth of their daughter, they made a second foray into fashion, launching Frances Valentine, a handbag-and-shoe company, in 2015. That company was sold to luxury competitor Coach past year in a $2.4 billion deal.