Kate Spade, the designer who built a fashion empire on her signature handbags before selling the brand, was found dead in her New York City apartment on Tuesday morning in an apparent suicide, police said.

Spade, 55, hanged herself and was found by her housekeeper at her home on Park Avenue on Manhattan's Upper East Side, the New York Daily News reported, citing unnamed police officials.

Born Katherine Noel Brosnahan, the Kansas City, Missouri, native was a former accessories editor at the now-closed Mademoiselle magazine before she and Andy Spade launched their namesake design company, Kate Spade New York, in 1993. The couple married the following year.

They began by selling handbags before expanding to include clothing, jewelry, bedding, legwear and fragrances.

The brand grew into a fashion empire, known for accessories that offered affordable luxury to younger working women. Her brightly colored, clean-lined style offered a spunky take on fashion at time when luxury handbags were out of reach to most consumers, and the industry was dominated by venerable European brands.

The couple sold the brand in 2006. In 2016, they launched a new fashion brand called Frances Valentine, which sells footwear and accessories.

Tapestry Inc, the handbag company formerly known as Coach, eventually bought the Kate Spade brand in May 2017 to tap millennials, who are drawn to the company's quirky satchels and colorful tote bags.

The deal also turned Coach into a multi-brand fashion house, a strategy that European counterparts such as Louis Vuitton have built their businesses on.

Kate Spade New York released a statement calling the news "incredibly sad."

"Although Kate has not been affiliated with the brand for more than a decade, she and her husband and creative partner, Andy, were the founders of our beloved brand," the statement said. "Kate will be dearly missed."

The New York Police Department confirmed the designer's death under her birth name. Spade's business representatives did not respond to a request for comment.

Fans of the brand began posting pictures of their favorite handbags on social media in reaction to the death. Chelsea Clinton, daughter of former U.S. President Bill Clinton, was among celebrities to mourn Spade on social media.

"My grandmother gave me my first Kate Spade bag when I was in college," she wrote on Twitter. "I still have it."

The singer Josh Groban also extended condolences. "Depression does not discriminate and comes without warning," he wrote on Twitter. "RIP Kate Spade."