The 55-year-old left a note at the scene and was found by housekeeping at about 10:20 a.m. It's not clear how long she had been dead. The medical examiner will perform an autopsy.
The officials said she was found with a red scarf around her neck attached to a doorknob. The officials were not authorized to speak publicly and spoke to The Associated Press on condition of anonymity.
The company she founded, Kate Spade New York, now has over 140 retail shops and outlet stores across the U.S. and more than 175 shops internationally.
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Spade, who was an accessories editor at Mademoiselle magazine, launched her company with husband Andy in their apartment in 1993. She started the company based on six shapes of bags that she thought every working woman needed. It created a smash.
"I grew up in the Midwest, where you have to have it (a fashion item) because you like it, not because you're supposed to have it," the Kansas City, Mo., native told The Associated Press in 2004. "For our customers, fashion is in the right place in their life. It's an adornment, not an obsession."
From the original boxy handbags, she expanded into shoes, luggage and other accessories, as well as a home line, stationery, and three books. Spade won multiple awards from the Council of Fashion Designers of America and was named a "giant of design" by House Beautiful magazine.
"As an accessory, a great bag that takes the outfit somewhere else is interesting," she told the AP in a 2000 interview.
She walked away from the company in 2007, a year after it was acquired from the Neiman Marcus Group for $125 million by the company then known as Liz Claiborne Inc.
Coach, now known as Tapestry, bought the Kate Spade brand last year for $2.4 billion, seeking to broaden its appeal.
Meanwhile, Spade and her husband started a new handbag company a few years ago, Frances Valentine. And she changed her name to Katherine Noel Frances Valentine Brosnahan Spade, she said in an NPR interview this year.
In addition to her husband, Spade is survived by a daughter, born in 2005.
The National Suicide Prevention Lifeline is a free, 24/7 service that can provide people who are suicidal or those around them with support, information and local resources. For help, please call 800-273-TALK (8255).
Today fashion icon Kate Spade was found dead of an apparent suicide at her home. You never know who needs help and your decision to RT this could put this number in front of someone who needs to see it. https://t.co/QiVbDeYqlG pic.twitter.com/YRRU1wVGrb— ABC13 Houston (@abc13houston) June 5, 2018