L'Wren Scott, who left her small-town Utah home as a teenager to become a model in Paris, then a top Hollywood stylist and finally a high-end fashion designer best known as the longtime girlfriend of Mick Jagger, has died in what was being investigated as an apparent suicide.

Scott was found dead in her Manhattan apartment at 10 a.m. Monday; no note was found and there was no sign of foul play, police said. The designer had texted her assistant 90 minutes earlier and asked her to come to her apartment but didn't say why. She was found kneeling with a scarf wrapped around her neck that had been tied to the handle of a French door, police said.

Her spokesperson requested privacy for her family and friends. Just last month Scott, who was believed to be 49 but had not disclosed her precise age, canceled her London Fashion Week show, due to reported production delays.

Jagger's representative said the singer was "completely shocked and devastated by the news" of her death.

Scott, whose elegant designs in lush fabrics were favored by celebrities like Madonna, Nicole Kidman, Oprah Winfrey, Penelope Cruz and first lady Michelle Obama, was a fixture on Jagger's arm since she met the Rolling Stones frontman in 2001. On red carpets, the striking 6-foot-3 designer towered over her famous 5-foot-10 boyfriend.

In 2006, five years after they became a couple, Scott founded her eponymous label, with an initial collection based on the "Little Black Dress." She became known for designs that had a vintage feel and bared little skin, like her famous "headmistress" dress - prim, with three-quarter sleeves, but also close-fitting and stylish.

Madonna was one of those who wore the dress. "This is a horrible and tragic loss," the singer said in a statement released by her publicist. "I'm so upset. I loved L'Wren's work and she was always so generous with me."