UPDATE: Kate Spade, the world-renowned fashion designer whose namesake brand is synonymous with cheerful luxury, was found dead in her New York City apartment on Tuesday morning, a senior law enforcement official with direct knowledge of the matter said. She was 55.

Her death is being investigated as an apparent suicide, four senior law enforcement officials said. It appeared she hanged herself with a scarf, sources told NBC New York.

Spade launched a line of chic handbags in the early 1990s that became a global sensation, turning her company, Kate Spade New York, into a retail powerhouse with over 140 shops and outlet stores across the United States.

"I was looking for something that could be less serious, more personal," Spade said of her handbags in a 1999 interview with the Boston Globe. "I also wanted timelessness."

The bags that bore her company's iconic logo put a contemporary spin on the classic elegance of American style icons like Audrey Hepburn and Jackie Kennedy. The designs were hailed as simple yet sophisticated, setting a brightly-colored and preppy fashion template for women around the world.

"I grew up in the Midwest, where you have to have [a fashion item] because you like it, not because you're supposed to have it," Spade 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."

She was born Kate Brosnahan in Kansas City, Missouri, in December 1962, the daughter of a construction company owner and a housewife. She co-founded her company in 1993, and over the next decade built it into an empire that also included shoes, luggage, stationery and other accessories.

Spade exited the company in 2007, after it was scooped up from the Neiman Marcus Group for $125 million by the company then known as Liz Claiborne Inc. Ten years later, Coach, now known as Tapestry Inc., acquired the brand for $2.4 billion.

She recently launched Frances Valentine, a line of what Vogue described as "modestly priced, ultra-covetable Italian-made shoes and bags," and reportedly even changed her surname to Valentine.

She is survived by her husband and a daughter, born in 2005. She was the sister-in-law of "Saturday Night Live" alum David Spade and the aunt of actress Rachel Brosnahan, star of the Amazon series "The Marvelous Mrs. Maisel."